diff --git a/LibreMetaverse/Animations.cs b/LibreMetaverse/Animations.cs
index 79fe96fb..7fb5d7dc 100644
--- a/LibreMetaverse/Animations.cs
+++ b/LibreMetaverse/Animations.cs
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2006-2016, openmetaverse.co
+ * Copyright (c) 2025, Sjofn LLC.
  * All rights reserved.
  *
  * - Redistribution and use in source and binary forms, with or without
@@ -27,6 +28,7 @@
 using System;
 using System.Reflection;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 
 namespace OpenMetaverse
 {
@@ -36,291 +38,292 @@ namespace OpenMetaverse
     public static class Animations
     {
         /// <summary>Agent with afraid expression on face</summary>
-        public readonly static UUID AFRAID = new UUID("6b61c8e8-4747-0d75-12d7-e49ff207a4ca");
+        public static readonly UUID AFRAID = new UUID("6b61c8e8-4747-0d75-12d7-e49ff207a4ca");
         /// <summary>Agent aiming a bazooka (right handed)</summary>
-        public readonly static UUID AIM_BAZOOKA_R = new UUID("b5b4a67d-0aee-30d2-72cd-77b333e932ef");
-        /// <summary>Agent aiming a bow (left handed)</summary>
-        public readonly static UUID AIM_BOW_L = new UUID("46bb4359-de38-4ed8-6a22-f1f52fe8f506");
-        /// <summary>Agent aiming a hand gun (right handed)</summary>
-        public readonly static UUID AIM_HANDGUN_R = new UUID("3147d815-6338-b932-f011-16b56d9ac18b");
-        /// <summary>Agent aiming a rifle (right handed)</summary>
-        public readonly static UUID AIM_RIFLE_R = new UUID("ea633413-8006-180a-c3ba-96dd1d756720");
+        public static readonly UUID AIM_BAZOOKA_R = new UUID("b5b4a67d-0aee-30d2-72cd-77b333e932ef");
+        /// <summary>Agent aiming a bow (left-handed)</summary>
+        public static readonly UUID AIM_BOW_L = new UUID("46bb4359-de38-4ed8-6a22-f1f52fe8f506");
+        /// <summary>Agent aiming a hand gun (right-handed)</summary>
+        public static readonly UUID AIM_HANDGUN_R = new UUID("3147d815-6338-b932-f011-16b56d9ac18b");
+        /// <summary>Agent aiming a rifle (right-handed)</summary>
+        public static readonly UUID AIM_RIFLE_R = new UUID("ea633413-8006-180a-c3ba-96dd1d756720");
         /// <summary>Agent with angry expression on face</summary>
-        public readonly static UUID ANGRY = new UUID("5747a48e-073e-c331-f6f3-7c2149613d3e");
+        public static readonly UUID ANGRY = new UUID("5747a48e-073e-c331-f6f3-7c2149613d3e");
         /// <summary>Agent hunched over (away)</summary>
-        public readonly static UUID AWAY = new UUID("fd037134-85d4-f241-72c6-4f42164fedee");
+        public static readonly UUID AWAY = new UUID("fd037134-85d4-f241-72c6-4f42164fedee");
         /// <summary>Agent doing a backflip</summary>
-        public readonly static UUID BACKFLIP = new UUID("c4ca6188-9127-4f31-0158-23c4e2f93304");
+        public static readonly UUID BACKFLIP = new UUID("c4ca6188-9127-4f31-0158-23c4e2f93304");
         /// <summary>Agent laughing while holding belly</summary>
-        public readonly static UUID BELLY_LAUGH = new UUID("18b3a4b5-b463-bd48-e4b6-71eaac76c515");
+        public static readonly UUID BELLY_LAUGH = new UUID("18b3a4b5-b463-bd48-e4b6-71eaac76c515");
         /// <summary>Agent blowing a kiss</summary>
-        public readonly static UUID BLOW_KISS = new UUID("db84829b-462c-ee83-1e27-9bbee66bd624");
+        public static readonly UUID BLOW_KISS = new UUID("db84829b-462c-ee83-1e27-9bbee66bd624");
         /// <summary>Agent with bored expression on face</summary>
-        public readonly static UUID BORED = new UUID("b906c4ba-703b-1940-32a3-0c7f7d791510");
+        public static readonly UUID BORED = new UUID("b906c4ba-703b-1940-32a3-0c7f7d791510");
         /// <summary>Agent bowing to audience</summary>
-        public readonly static UUID BOW = new UUID("82e99230-c906-1403-4d9c-3889dd98daba");
+        public static readonly UUID BOW = new UUID("82e99230-c906-1403-4d9c-3889dd98daba");
         /// <summary>Agent brushing himself/herself off</summary>
-        public readonly static UUID BRUSH = new UUID("349a3801-54f9-bf2c-3bd0-1ac89772af01");
+        public static readonly UUID BRUSH = new UUID("349a3801-54f9-bf2c-3bd0-1ac89772af01");
         /// <summary>Agent in busy mode</summary>
-        public readonly static UUID BUSY = new UUID("efcf670c-2d18-8128-973a-034ebc806b67");
+        public static readonly UUID BUSY = new UUID("efcf670c-2d18-8128-973a-034ebc806b67");
         /// <summary>Agent clapping hands</summary>
-        public readonly static UUID CLAP = new UUID("9b0c1c4e-8ac7-7969-1494-28c874c4f668");
-        /// <summary>Agent doing a curtsey bow</summary>
-        public readonly static UUID COURTBOW = new UUID("9ba1c942-08be-e43a-fb29-16ad440efc50");
+        public static readonly UUID CLAP = new UUID("9b0c1c4e-8ac7-7969-1494-28c874c4f668");
+        /// <summary>Agent doing a curtsy bow</summary>
+        public static readonly UUID COURTBOW = new UUID("9ba1c942-08be-e43a-fb29-16ad440efc50");
         /// <summary>Agent crouching</summary>
-        public readonly static UUID CROUCH = new UUID("201f3fdf-cb1f-dbec-201f-7333e328ae7c");
+        public static readonly UUID CROUCH = new UUID("201f3fdf-cb1f-dbec-201f-7333e328ae7c");
         /// <summary>Agent crouching while walking</summary>
-        public readonly static UUID CROUCHWALK = new UUID("47f5f6fb-22e5-ae44-f871-73aaaf4a6022");
+        public static readonly UUID CROUCHWALK = new UUID("47f5f6fb-22e5-ae44-f871-73aaaf4a6022");
         /// <summary>Agent crying</summary>
-        public readonly static UUID CRY = new UUID("92624d3e-1068-f1aa-a5ec-8244585193ed");
+        public static readonly UUID CRY = new UUID("92624d3e-1068-f1aa-a5ec-8244585193ed");
         /// <summary>Agent unanimated with arms out (e.g. setting appearance)</summary>
-        public readonly static UUID CUSTOMIZE = new UUID("038fcec9-5ebd-8a8e-0e2e-6e71a0a1ac53");
+        public static readonly UUID CUSTOMIZE = new UUID("038fcec9-5ebd-8a8e-0e2e-6e71a0a1ac53");
         /// <summary>Agent re-animated after set appearance finished</summary>
-        public readonly static UUID CUSTOMIZE_DONE = new UUID("6883a61a-b27b-5914-a61e-dda118a9ee2c");
+        public static readonly UUID CUSTOMIZE_DONE = new UUID("6883a61a-b27b-5914-a61e-dda118a9ee2c");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE1 = new UUID("b68a3d7c-de9e-fc87-eec8-543d787e5b0d");
+        public static readonly UUID DANCE1 = new UUID("b68a3d7c-de9e-fc87-eec8-543d787e5b0d");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE2 = new UUID("928cae18-e31d-76fd-9cc9-2f55160ff818");
+        public static readonly UUID DANCE2 = new UUID("928cae18-e31d-76fd-9cc9-2f55160ff818");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE3 = new UUID("30047778-10ea-1af7-6881-4db7a3a5a114");
+        public static readonly UUID DANCE3 = new UUID("30047778-10ea-1af7-6881-4db7a3a5a114");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE4 = new UUID("951469f4-c7b2-c818-9dee-ad7eea8c30b7");
+        public static readonly UUID DANCE4 = new UUID("951469f4-c7b2-c818-9dee-ad7eea8c30b7");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE5 = new UUID("4bd69a1d-1114-a0b4-625f-84e0a5237155");
+        public static readonly UUID DANCE5 = new UUID("4bd69a1d-1114-a0b4-625f-84e0a5237155");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE6 = new UUID("cd28b69b-9c95-bb78-3f94-8d605ff1bb12");
+        public static readonly UUID DANCE6 = new UUID("cd28b69b-9c95-bb78-3f94-8d605ff1bb12");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE7 = new UUID("a54d8ee2-28bb-80a9-7f0c-7afbbe24a5d6");
+        public static readonly UUID DANCE7 = new UUID("a54d8ee2-28bb-80a9-7f0c-7afbbe24a5d6");
         /// <summary>Agent dancing</summary>
-        public readonly static UUID DANCE8 = new UUID("b0dc417c-1f11-af36-2e80-7e7489fa7cdc");
+        public static readonly UUID DANCE8 = new UUID("b0dc417c-1f11-af36-2e80-7e7489fa7cdc");
         /// <summary>Agent on ground unanimated</summary>
-        public readonly static UUID DEAD = new UUID("57abaae6-1d17-7b1b-5f98-6d11a6411276");
+        public static readonly UUID DEAD = new UUID("57abaae6-1d17-7b1b-5f98-6d11a6411276");
         /// <summary>Agent boozing it up</summary>
-        public readonly static UUID DRINK = new UUID("0f86e355-dd31-a61c-fdb0-3a96b9aad05f");
+        public static readonly UUID DRINK = new UUID("0f86e355-dd31-a61c-fdb0-3a96b9aad05f");
         /// <summary>Agent with embarassed expression on face</summary>
-        public readonly static UUID EMBARRASSED = new UUID("514af488-9051-044a-b3fc-d4dbf76377c6");
+        public static readonly UUID EMBARRASSED = new UUID("514af488-9051-044a-b3fc-d4dbf76377c6");
         /// <summary>Agent with afraid expression on face</summary>
-        public readonly static UUID EXPRESS_AFRAID = new UUID("aa2df84d-cf8f-7218-527b-424a52de766e");
+        public static readonly UUID EXPRESS_AFRAID = new UUID("aa2df84d-cf8f-7218-527b-424a52de766e");
         /// <summary>Agent with angry expression on face</summary>
-        public readonly static UUID EXPRESS_ANGER = new UUID("1a03b575-9634-b62a-5767-3a679e81f4de");
+        public static readonly UUID EXPRESS_ANGER = new UUID("1a03b575-9634-b62a-5767-3a679e81f4de");
         /// <summary>Agent with bored expression on face</summary>
-        public readonly static UUID EXPRESS_BORED = new UUID("214aa6c1-ba6a-4578-f27c-ce7688f61d0d");
+        public static readonly UUID EXPRESS_BORED = new UUID("214aa6c1-ba6a-4578-f27c-ce7688f61d0d");
         /// <summary>Agent crying</summary>
-        public readonly static UUID EXPRESS_CRY = new UUID("d535471b-85bf-3b4d-a542-93bea4f59d33");
+        public static readonly UUID EXPRESS_CRY = new UUID("d535471b-85bf-3b4d-a542-93bea4f59d33");
         /// <summary>Agent showing disdain (dislike) for something</summary>
-        public readonly static UUID EXPRESS_DISDAIN = new UUID("d4416ff1-09d3-300f-4183-1b68a19b9fc1");
-        /// <summary>Agent with embarassed expression on face</summary>
-        public readonly static UUID EXPRESS_EMBARRASSED = new UUID("0b8c8211-d78c-33e8-fa28-c51a9594e424");
+        public static readonly UUID EXPRESS_DISDAIN = new UUID("d4416ff1-09d3-300f-4183-1b68a19b9fc1");
+        /// <summary>Agent with embarrassed expression on face</summary>
+        public static readonly UUID EXPRESS_EMBARRASSED = new UUID("0b8c8211-d78c-33e8-fa28-c51a9594e424");
         /// <summary>Agent with frowning expression on face</summary>
-        public readonly static UUID EXPRESS_FROWN = new UUID("fee3df48-fa3d-1015-1e26-a205810e3001");
+        public static readonly UUID EXPRESS_FROWN = new UUID("fee3df48-fa3d-1015-1e26-a205810e3001");
         /// <summary>Agent with kissy face</summary>
-        public readonly static UUID EXPRESS_KISS = new UUID("1e8d90cc-a84e-e135-884c-7c82c8b03a14");
-        /// <summary>Agent expressing laughgter</summary>
-        public readonly static UUID EXPRESS_LAUGH = new UUID("62570842-0950-96f8-341c-809e65110823");
+        public static readonly UUID EXPRESS_KISS = new UUID("1e8d90cc-a84e-e135-884c-7c82c8b03a14");
+        /// <summary>Agent expressing laughter</summary>
+        public static readonly UUID EXPRESS_LAUGH = new UUID("62570842-0950-96f8-341c-809e65110823");
         /// <summary>Agent with open mouth</summary>
-        public readonly static UUID EXPRESS_OPEN_MOUTH = new UUID("d63bc1f9-fc81-9625-a0c6-007176d82eb7");
+        public static readonly UUID EXPRESS_OPEN_MOUTH = new UUID("d63bc1f9-fc81-9625-a0c6-007176d82eb7");
         /// <summary>Agent with repulsed expression on face</summary>
-        public readonly static UUID EXPRESS_REPULSED = new UUID("f76cda94-41d4-a229-2872-e0296e58afe1");
+        public static readonly UUID EXPRESS_REPULSED = new UUID("f76cda94-41d4-a229-2872-e0296e58afe1");
         /// <summary>Agent expressing sadness</summary>
-        public readonly static UUID EXPRESS_SAD = new UUID("eb6ebfb2-a4b3-a19c-d388-4dd5c03823f7");
+        public static readonly UUID EXPRESS_SAD = new UUID("eb6ebfb2-a4b3-a19c-d388-4dd5c03823f7");
         /// <summary>Agent shrugging shoulders</summary>
-        public readonly static UUID EXPRESS_SHRUG = new UUID("a351b1bc-cc94-aac2-7bea-a7e6ebad15ef");
+        public static readonly UUID EXPRESS_SHRUG = new UUID("a351b1bc-cc94-aac2-7bea-a7e6ebad15ef");
         /// <summary>Agent with a smile</summary>
-        public readonly static UUID EXPRESS_SMILE = new UUID("b7c7c833-e3d3-c4e3-9fc0-131237446312");
+        public static readonly UUID EXPRESS_SMILE = new UUID("b7c7c833-e3d3-c4e3-9fc0-131237446312");
         /// <summary>Agent expressing surprise</summary>
-        public readonly static UUID EXPRESS_SURPRISE = new UUID("728646d9-cc79-08b2-32d6-937f0a835c24");
+        public static readonly UUID EXPRESS_SURPRISE = new UUID("728646d9-cc79-08b2-32d6-937f0a835c24");
         /// <summary>Agent sticking tongue out</summary>
-        public readonly static UUID EXPRESS_TONGUE_OUT = new UUID("835965c6-7f2f-bda2-5deb-2478737f91bf");
+        public static readonly UUID EXPRESS_TONGUE_OUT = new UUID("835965c6-7f2f-bda2-5deb-2478737f91bf");
         /// <summary>Agent with big toothy smile</summary>
-        public readonly static UUID EXPRESS_TOOTHSMILE = new UUID("b92ec1a5-e7ce-a76b-2b05-bcdb9311417e");
+        public static readonly UUID EXPRESS_TOOTHSMILE = new UUID("b92ec1a5-e7ce-a76b-2b05-bcdb9311417e");
         /// <summary>Agent winking</summary>
-        public readonly static UUID EXPRESS_WINK = new UUID("da020525-4d94-59d6-23d7-81fdebf33148");
+        public static readonly UUID EXPRESS_WINK = new UUID("da020525-4d94-59d6-23d7-81fdebf33148");
         /// <summary>Agent expressing worry</summary>
-        public readonly static UUID EXPRESS_WORRY = new UUID("9c05e5c7-6f07-6ca4-ed5a-b230390c3950");
+        public static readonly UUID EXPRESS_WORRY = new UUID("9c05e5c7-6f07-6ca4-ed5a-b230390c3950");
         /// <summary>Agent falling down</summary>
-        public readonly static UUID FALLDOWN = new UUID("666307d9-a860-572d-6fd4-c3ab8865c094");
+        public static readonly UUID FALLDOWN = new UUID("666307d9-a860-572d-6fd4-c3ab8865c094");
         /// <summary>Agent walking (feminine version)</summary>
-        public readonly static UUID FEMALE_WALK = new UUID("f5fc7433-043d-e819-8298-f519a119b688");
+        public static readonly UUID FEMALE_WALK = new UUID("f5fc7433-043d-e819-8298-f519a119b688");
         /// <summary>Agent wagging finger (disapproval)</summary>
-        public readonly static UUID FINGER_WAG = new UUID("c1bc7f36-3ba0-d844-f93c-93be945d644f");
-        /// <summary>I'm not sure I want to know</summary>
-        public readonly static UUID FIST_PUMP = new UUID("7db00ccd-f380-f3ee-439d-61968ec69c8a");
+        public static readonly UUID FINGER_WAG = new UUID("c1bc7f36-3ba0-d844-f93c-93be945d644f");
+        /// <summary>Agent pumps fist up and down</summary>
+        public static readonly UUID FIST_PUMP = new UUID("7db00ccd-f380-f3ee-439d-61968ec69c8a");
         /// <summary>Agent in superman position</summary>
-        public readonly static UUID FLY = new UUID("aec4610c-757f-bc4e-c092-c6e9caf18daf");
+        public static readonly UUID FLY = new UUID("aec4610c-757f-bc4e-c092-c6e9caf18daf");
         /// <summary>Agent in superman position</summary>
-        public readonly static UUID FLYSLOW = new UUID("2b5a38b2-5e00-3a97-a495-4c826bc443e6");
+        public static readonly UUID FLYSLOW = new UUID("2b5a38b2-5e00-3a97-a495-4c826bc443e6");
         /// <summary>Agent greeting another</summary>
-        public readonly static UUID HELLO = new UUID("9b29cd61-c45b-5689-ded2-91756b8d76a9");
-        /// <summary>Agent holding bazooka (right handed)</summary>
-        public readonly static UUID HOLD_BAZOOKA_R = new UUID("ef62d355-c815-4816-2474-b1acc21094a6");
-        /// <summary>Agent holding a bow (left handed)</summary>
-        public readonly static UUID HOLD_BOW_L = new UUID("8b102617-bcba-037b-86c1-b76219f90c88");
-        /// <summary>Agent holding a handgun (right handed)</summary>
-        public readonly static UUID HOLD_HANDGUN_R = new UUID("efdc1727-8b8a-c800-4077-975fc27ee2f2");
-        /// <summary>Agent holding a rifle (right handed)</summary>
-        public readonly static UUID HOLD_RIFLE_R = new UUID("3d94bad0-c55b-7dcc-8763-033c59405d33");
-        /// <summary>Agent throwing an object (right handed)</summary>
-        public readonly static UUID HOLD_THROW_R = new UUID("7570c7b5-1f22-56dd-56ef-a9168241bbb6");
+        public static readonly UUID HELLO = new UUID("9b29cd61-c45b-5689-ded2-91756b8d76a9");
+        /// <summary>Agent holding bazooka (right-handed)</summary>
+        public static readonly UUID HOLD_BAZOOKA_R = new UUID("ef62d355-c815-4816-2474-b1acc21094a6");
+        /// <summary>Agent holding a bow (left-handed)</summary>
+        public static readonly UUID HOLD_BOW_L = new UUID("8b102617-bcba-037b-86c1-b76219f90c88");
+        /// <summary>Agent holding a handgun (right-handed)</summary>
+        public static readonly UUID HOLD_HANDGUN_R = new UUID("efdc1727-8b8a-c800-4077-975fc27ee2f2");
+        /// <summary>Agent holding a rifle (right-handed)</summary>
+        public static readonly UUID HOLD_RIFLE_R = new UUID("3d94bad0-c55b-7dcc-8763-033c59405d33");
+        /// <summary>Agent throwing an object (right-handed)</summary>
+        public static readonly UUID HOLD_THROW_R = new UUID("7570c7b5-1f22-56dd-56ef-a9168241bbb6");
         /// <summary>Agent in static hover</summary>
-        public readonly static UUID HOVER = new UUID("4ae8016b-31b9-03bb-c401-b1ea941db41d");
+        public static readonly UUID HOVER = new UUID("4ae8016b-31b9-03bb-c401-b1ea941db41d");
         /// <summary>Agent hovering downward</summary>
-        public readonly static UUID HOVER_DOWN = new UUID("20f063ea-8306-2562-0b07-5c853b37b31e");
+        public static readonly UUID HOVER_DOWN = new UUID("20f063ea-8306-2562-0b07-5c853b37b31e");
         /// <summary>Agent hovering upward</summary>
-        public readonly static UUID HOVER_UP = new UUID("62c5de58-cb33-5743-3d07-9e4cd4352864");
+        public static readonly UUID HOVER_UP = new UUID("62c5de58-cb33-5743-3d07-9e4cd4352864");
         /// <summary>Agent being impatient</summary>
-        public readonly static UUID IMPATIENT = new UUID("5ea3991f-c293-392e-6860-91dfa01278a3");
+        public static readonly UUID IMPATIENT = new UUID("5ea3991f-c293-392e-6860-91dfa01278a3");
         /// <summary>Agent jumping</summary>
-        public readonly static UUID JUMP = new UUID("2305bd75-1ca9-b03b-1faa-b176b8a8c49e");
+        public static readonly UUID JUMP = new UUID("2305bd75-1ca9-b03b-1faa-b176b8a8c49e");
         /// <summary>Agent jumping with fervor</summary>
-        public readonly static UUID JUMP_FOR_JOY = new UUID("709ea28e-1573-c023-8bf8-520c8bc637fa");
+        public static readonly UUID JUMP_FOR_JOY = new UUID("709ea28e-1573-c023-8bf8-520c8bc637fa");
         /// <summary>Agent point to lips then rear end</summary>
-        public readonly static UUID KISS_MY_BUTT = new UUID("19999406-3a3a-d58c-a2ac-d72e555dcf51");
+        public static readonly UUID KISS_MY_BUTT = new UUID("19999406-3a3a-d58c-a2ac-d72e555dcf51");
         /// <summary>Agent landing from jump, finished flight, etc</summary>
-        public readonly static UUID LAND = new UUID("7a17b059-12b2-41b1-570a-186368b6aa6f");
+        public static readonly UUID LAND = new UUID("7a17b059-12b2-41b1-570a-186368b6aa6f");
         /// <summary>Agent laughing</summary>
-        public readonly static UUID LAUGH_SHORT = new UUID("ca5b3f14-3194-7a2b-c894-aa699b718d1f");
+        public static readonly UUID LAUGH_SHORT = new UUID("ca5b3f14-3194-7a2b-c894-aa699b718d1f");
         /// <summary>Agent landing from jump, finished flight, etc</summary>
-        public readonly static UUID MEDIUM_LAND = new UUID("f4f00d6e-b9fe-9292-f4cb-0ae06ea58d57");
+        public static readonly UUID MEDIUM_LAND = new UUID("f4f00d6e-b9fe-9292-f4cb-0ae06ea58d57");
         /// <summary>Agent sitting on a motorcycle</summary>
-        public readonly static UUID MOTORCYCLE_SIT = new UUID("08464f78-3a8e-2944-cba5-0c94aff3af29");
+        public static readonly UUID MOTORCYCLE_SIT = new UUID("08464f78-3a8e-2944-cba5-0c94aff3af29");
         /// <summary></summary>
-        public readonly static UUID MUSCLE_BEACH = new UUID("315c3a41-a5f3-0ba4-27da-f893f769e69b");
+        public static readonly UUID MUSCLE_BEACH = new UUID("315c3a41-a5f3-0ba4-27da-f893f769e69b");
         /// <summary>Agent moving head side to side</summary>
-        public readonly static UUID NO = new UUID("5a977ed9-7f72-44e9-4c4c-6e913df8ae74");
+        public static readonly UUID NO = new UUID("5a977ed9-7f72-44e9-4c4c-6e913df8ae74");
         /// <summary>Agent moving head side to side with unhappy expression</summary>
-        public readonly static UUID NO_UNHAPPY = new UUID("d83fa0e5-97ed-7eb2-e798-7bd006215cb4");
+        public static readonly UUID NO_UNHAPPY = new UUID("d83fa0e5-97ed-7eb2-e798-7bd006215cb4");
         /// <summary>Agent taunting another</summary>
-        public readonly static UUID NYAH_NYAH = new UUID("f061723d-0a18-754f-66ee-29a44795a32f");
+        public static readonly UUID NYAH_NYAH = new UUID("f061723d-0a18-754f-66ee-29a44795a32f");
         /// <summary></summary>
-        public readonly static UUID ONETWO_PUNCH = new UUID("eefc79be-daae-a239-8c04-890f5d23654a");
+        public static readonly UUID ONETWO_PUNCH = new UUID("eefc79be-daae-a239-8c04-890f5d23654a");
         /// <summary>Agent giving peace sign</summary>
-        public readonly static UUID PEACE = new UUID("b312b10e-65ab-a0a4-8b3c-1326ea8e3ed9");
+        public static readonly UUID PEACE = new UUID("b312b10e-65ab-a0a4-8b3c-1326ea8e3ed9");
         /// <summary>Agent pointing at self</summary>
-        public readonly static UUID POINT_ME = new UUID("17c024cc-eef2-f6a0-3527-9869876d7752");
+        public static readonly UUID POINT_ME = new UUID("17c024cc-eef2-f6a0-3527-9869876d7752");
         /// <summary>Agent pointing at another</summary>
-        public readonly static UUID POINT_YOU = new UUID("ec952cca-61ef-aa3b-2789-4d1344f016de");
+        public static readonly UUID POINT_YOU = new UUID("ec952cca-61ef-aa3b-2789-4d1344f016de");
         /// <summary>Agent preparing for jump (bending knees)</summary>
-        public readonly static UUID PRE_JUMP = new UUID("7a4e87fe-de39-6fcb-6223-024b00893244");
+        public static readonly UUID PRE_JUMP = new UUID("7a4e87fe-de39-6fcb-6223-024b00893244");
         /// <summary>Agent punching with left hand</summary>
-        public readonly static UUID PUNCH_LEFT = new UUID("f3300ad9-3462-1d07-2044-0fef80062da0");
+        public static readonly UUID PUNCH_LEFT = new UUID("f3300ad9-3462-1d07-2044-0fef80062da0");
         /// <summary>Agent punching with right hand</summary>
-        public readonly static UUID PUNCH_RIGHT = new UUID("c8e42d32-7310-6906-c903-cab5d4a34656");
+        public static readonly UUID PUNCH_RIGHT = new UUID("c8e42d32-7310-6906-c903-cab5d4a34656");
         /// <summary>Agent acting repulsed</summary>
-        public readonly static UUID REPULSED = new UUID("36f81a92-f076-5893-dc4b-7c3795e487cf");
+        public static readonly UUID REPULSED = new UUID("36f81a92-f076-5893-dc4b-7c3795e487cf");
         /// <summary>Agent trying to be Chuck Norris</summary>
-        public readonly static UUID ROUNDHOUSE_KICK = new UUID("49aea43b-5ac3-8a44-b595-96100af0beda");
+        public static readonly UUID ROUNDHOUSE_KICK = new UUID("49aea43b-5ac3-8a44-b595-96100af0beda");
         /// <summary>Rocks, Paper, Scissors 1, 2, 3</summary>
-        public readonly static UUID RPS_COUNTDOWN = new UUID("35db4f7e-28c2-6679-cea9-3ee108f7fc7f");
+        public static readonly UUID RPS_COUNTDOWN = new UUID("35db4f7e-28c2-6679-cea9-3ee108f7fc7f");
         /// <summary>Agent with hand flat over other hand</summary>
-        public readonly static UUID RPS_PAPER = new UUID("0836b67f-7f7b-f37b-c00a-460dc1521f5a");
+        public static readonly UUID RPS_PAPER = new UUID("0836b67f-7f7b-f37b-c00a-460dc1521f5a");
         /// <summary>Agent with fist over other hand</summary>
-        public readonly static UUID RPS_ROCK = new UUID("42dd95d5-0bc6-6392-f650-777304946c0f");
+        public static readonly UUID RPS_ROCK = new UUID("42dd95d5-0bc6-6392-f650-777304946c0f");
         /// <summary>Agent with two fingers spread over other hand</summary>
-        public readonly static UUID RPS_SCISSORS = new UUID("16803a9f-5140-e042-4d7b-d28ba247c325");
+        public static readonly UUID RPS_SCISSORS = new UUID("16803a9f-5140-e042-4d7b-d28ba247c325");
         /// <summary>Agent running</summary>
-        public readonly static UUID RUN = new UUID("05ddbff8-aaa9-92a1-2b74-8fe77a29b445");
+        public static readonly UUID RUN = new UUID("05ddbff8-aaa9-92a1-2b74-8fe77a29b445");
         /// <summary>Agent appearing sad</summary>
-        public readonly static UUID SAD = new UUID("0eb702e2-cc5a-9a88-56a5-661a55c0676a");
+        public static readonly UUID SAD = new UUID("0eb702e2-cc5a-9a88-56a5-661a55c0676a");
         /// <summary>Agent saluting</summary>
-        public readonly static UUID SALUTE = new UUID("cd7668a6-7011-d7e2-ead8-fc69eff1a104");
-        /// <summary>Agent shooting bow (left handed)</summary>
-        public readonly static UUID SHOOT_BOW_L = new UUID("e04d450d-fdb5-0432-fd68-818aaf5935f8");
+        public static readonly UUID SALUTE = new UUID("cd7668a6-7011-d7e2-ead8-fc69eff1a104");
+        /// <summary>Agent shooting bow (left-handed)</summary>
+        public static readonly UUID SHOOT_BOW_L = new UUID("e04d450d-fdb5-0432-fd68-818aaf5935f8");
         /// <summary>Agent cupping mouth as if shouting</summary>
-        public readonly static UUID SHOUT = new UUID("6bd01860-4ebd-127a-bb3d-d1427e8e0c42");
+        public static readonly UUID SHOUT = new UUID("6bd01860-4ebd-127a-bb3d-d1427e8e0c42");
         /// <summary>Agent shrugging shoulders</summary>
-        public readonly static UUID SHRUG = new UUID("70ea714f-3a97-d742-1b01-590a8fcd1db5");
+        public static readonly UUID SHRUG = new UUID("70ea714f-3a97-d742-1b01-590a8fcd1db5");
         /// <summary>Agent in sit position</summary>
-        public readonly static UUID SIT = new UUID("1a5fe8ac-a804-8a5d-7cbd-56bd83184568");
+        public static readonly UUID SIT = new UUID("1a5fe8ac-a804-8a5d-7cbd-56bd83184568");
         /// <summary>Agent in sit position (feminine)</summary>
-        public readonly static UUID SIT_FEMALE = new UUID("b1709c8d-ecd3-54a1-4f28-d55ac0840782");
+        public static readonly UUID SIT_FEMALE = new UUID("b1709c8d-ecd3-54a1-4f28-d55ac0840782");
         /// <summary>Agent in sit position (generic)</summary>
-        public readonly static UUID SIT_GENERIC = new UUID("245f3c54-f1c0-bf2e-811f-46d8eeb386e7");
+        public static readonly UUID SIT_GENERIC = new UUID("245f3c54-f1c0-bf2e-811f-46d8eeb386e7");
         /// <summary>Agent sitting on ground</summary>
-        public readonly static UUID SIT_GROUND = new UUID("1c7600d6-661f-b87b-efe2-d7421eb93c86");
+        public static readonly UUID SIT_GROUND = new UUID("1c7600d6-661f-b87b-efe2-d7421eb93c86");
         /// <summary>Agent sitting on ground</summary>
-        public readonly static UUID SIT_GROUND_staticRAINED = new UUID("1a2bd58e-87ff-0df8-0b4c-53e047b0bb6e");
+        public static readonly UUID SIT_GROUND_staticRAINED = new UUID("1a2bd58e-87ff-0df8-0b4c-53e047b0bb6e");
         /// <summary></summary>
-        public readonly static UUID SIT_TO_STAND = new UUID("a8dee56f-2eae-9e7a-05a2-6fb92b97e21e");
+        public static readonly UUID SIT_TO_STAND = new UUID("a8dee56f-2eae-9e7a-05a2-6fb92b97e21e");
         /// <summary>Agent sleeping on side</summary>
-        public readonly static UUID SLEEP = new UUID("f2bed5f9-9d44-39af-b0cd-257b2a17fe40");
+        public static readonly UUID SLEEP = new UUID("f2bed5f9-9d44-39af-b0cd-257b2a17fe40");
         /// <summary>Agent smoking</summary>
-        public readonly static UUID SMOKE_IDLE = new UUID("d2f2ee58-8ad1-06c9-d8d3-3827ba31567a");
+        public static readonly UUID SMOKE_IDLE = new UUID("d2f2ee58-8ad1-06c9-d8d3-3827ba31567a");
         /// <summary>Agent inhaling smoke</summary>
-        public readonly static UUID SMOKE_INHALE = new UUID("6802d553-49da-0778-9f85-1599a2266526");
+        public static readonly UUID SMOKE_INHALE = new UUID("6802d553-49da-0778-9f85-1599a2266526");
         /// <summary></summary>
-        public readonly static UUID SMOKE_THROW_DOWN = new UUID("0a9fb970-8b44-9114-d3a9-bf69cfe804d6");
+        public static readonly UUID SMOKE_THROW_DOWN = new UUID("0a9fb970-8b44-9114-d3a9-bf69cfe804d6");
         /// <summary>Agent taking a picture</summary>
-        public readonly static UUID SNAPSHOT = new UUID("eae8905b-271a-99e2-4c0e-31106afd100c");
+        public static readonly UUID SNAPSHOT = new UUID("eae8905b-271a-99e2-4c0e-31106afd100c");
         /// <summary>Agent standing</summary>
-        public readonly static UUID STAND = new UUID("2408fe9e-df1d-1d7d-f4ff-1384fa7b350f");
+        public static readonly UUID STAND = new UUID("2408fe9e-df1d-1d7d-f4ff-1384fa7b350f");
         /// <summary>Agent standing up</summary>
-        public readonly static UUID STANDUP = new UUID("3da1d753-028a-5446-24f3-9c9b856d9422");
+        public static readonly UUID STANDUP = new UUID("3da1d753-028a-5446-24f3-9c9b856d9422");
         /// <summary>Agent standing</summary>
-        public readonly static UUID STAND_1 = new UUID("15468e00-3400-bb66-cecc-646d7c14458e");
+        public static readonly UUID STAND_1 = new UUID("15468e00-3400-bb66-cecc-646d7c14458e");
         /// <summary>Agent standing</summary>
-        public readonly static UUID STAND_2 = new UUID("370f3a20-6ca6-9971-848c-9a01bc42ae3c");
+        public static readonly UUID STAND_2 = new UUID("370f3a20-6ca6-9971-848c-9a01bc42ae3c");
         /// <summary>Agent standing</summary>
-        public readonly static UUID STAND_3 = new UUID("42b46214-4b44-79ae-deb8-0df61424ff4b");
+        public static readonly UUID STAND_3 = new UUID("42b46214-4b44-79ae-deb8-0df61424ff4b");
         /// <summary>Agent standing</summary>
-        public readonly static UUID STAND_4 = new UUID("f22fed8b-a5ed-2c93-64d5-bdd8b93c889f");
+        public static readonly UUID STAND_4 = new UUID("f22fed8b-a5ed-2c93-64d5-bdd8b93c889f");
         /// <summary>Agent stretching</summary>
-        public readonly static UUID STRETCH = new UUID("80700431-74ec-a008-14f8-77575e73693f");
+        public static readonly UUID STRETCH = new UUID("80700431-74ec-a008-14f8-77575e73693f");
         /// <summary>Agent in stride (fast walk)</summary>
-        public readonly static UUID STRIDE = new UUID("1cb562b0-ba21-2202-efb3-30f82cdf9595");
+        public static readonly UUID STRIDE = new UUID("1cb562b0-ba21-2202-efb3-30f82cdf9595");
         /// <summary>Agent surfing</summary>
-        public readonly static UUID SURF = new UUID("41426836-7437-7e89-025d-0aa4d10f1d69");
+        public static readonly UUID SURF = new UUID("41426836-7437-7e89-025d-0aa4d10f1d69");
         /// <summary>Agent acting surprised</summary>
-        public readonly static UUID SURPRISE = new UUID("313b9881-4302-73c0-c7d0-0e7a36b6c224");
+        public static readonly UUID SURPRISE = new UUID("313b9881-4302-73c0-c7d0-0e7a36b6c224");
         /// <summary>Agent striking with a sword</summary>
-        public readonly static UUID SWORD_STRIKE = new UUID("85428680-6bf9-3e64-b489-6f81087c24bd");
+        public static readonly UUID SWORD_STRIKE = new UUID("85428680-6bf9-3e64-b489-6f81087c24bd");
         /// <summary>Agent talking (lips moving)</summary>
-        public readonly static UUID TALK = new UUID("5c682a95-6da4-a463-0bf6-0f5b7be129d1");
+        public static readonly UUID TALK = new UUID("5c682a95-6da4-a463-0bf6-0f5b7be129d1");
         /// <summary>Agent throwing a tantrum</summary>
-        public readonly static UUID TANTRUM = new UUID("11000694-3f41-adc2-606b-eee1d66f3724");
-        /// <summary>Agent throwing an object (right handed)</summary>
-        public readonly static UUID THROW_R = new UUID("aa134404-7dac-7aca-2cba-435f9db875ca");
+        public static readonly UUID TANTRUM = new UUID("11000694-3f41-adc2-606b-eee1d66f3724");
+        /// <summary>Agent throwing an object (right-handed)</summary>
+        public static readonly UUID THROW_R = new UUID("aa134404-7dac-7aca-2cba-435f9db875ca");
         /// <summary>Agent trying on a shirt</summary>
-        public readonly static UUID TRYON_SHIRT = new UUID("83ff59fe-2346-f236-9009-4e3608af64c1");
+        public static readonly UUID TRYON_SHIRT = new UUID("83ff59fe-2346-f236-9009-4e3608af64c1");
         /// <summary>Agent turning to the left</summary>
-        public readonly static UUID TURNLEFT = new UUID("56e0ba0d-4a9f-7f27-6117-32f2ebbf6135");
+        public static readonly UUID TURNLEFT = new UUID("56e0ba0d-4a9f-7f27-6117-32f2ebbf6135");
         /// <summary>Agent turning to the right</summary>
-        public readonly static UUID TURNRIGHT = new UUID("2d6daa51-3192-6794-8e2e-a15f8338ec30");
+        public static readonly UUID TURNRIGHT = new UUID("2d6daa51-3192-6794-8e2e-a15f8338ec30");
         /// <summary>Agent typing</summary>
-        public readonly static UUID TYPE = new UUID("c541c47f-e0c0-058b-ad1a-d6ae3a4584d9");
+        public static readonly UUID TYPE = new UUID("c541c47f-e0c0-058b-ad1a-d6ae3a4584d9");
         /// <summary>Agent walking</summary>
-        public readonly static UUID WALK = new UUID("6ed24bd8-91aa-4b12-ccc7-c97c857ab4e0");
+        public static readonly UUID WALK = new UUID("6ed24bd8-91aa-4b12-ccc7-c97c857ab4e0");
         /// <summary>Agent whispering</summary>
-        public readonly static UUID WHISPER = new UUID("7693f268-06c7-ea71-fa21-2b30d6533f8f");
+        public static readonly UUID WHISPER = new UUID("7693f268-06c7-ea71-fa21-2b30d6533f8f");
         /// <summary>Agent whispering with fingers in mouth</summary>
-        public readonly static UUID WHISTLE = new UUID("b1ed7982-c68e-a982-7561-52a88a5298c0");
+        public static readonly UUID WHISTLE = new UUID("b1ed7982-c68e-a982-7561-52a88a5298c0");
         /// <summary>Agent winking</summary>
-        public readonly static UUID WINK = new UUID("869ecdad-a44b-671e-3266-56aef2e3ac2e");
+        public static readonly UUID WINK = new UUID("869ecdad-a44b-671e-3266-56aef2e3ac2e");
         /// <summary>Agent winking</summary>
-        public readonly static UUID WINK_HOLLYWOOD = new UUID("c0c4030f-c02b-49de-24ba-2331f43fe41c");
+        public static readonly UUID WINK_HOLLYWOOD = new UUID("c0c4030f-c02b-49de-24ba-2331f43fe41c");
         /// <summary>Agent worried</summary>
-        public readonly static UUID WORRY = new UUID("9f496bd2-589a-709f-16cc-69bf7df1d36c");
+        public static readonly UUID WORRY = new UUID("9f496bd2-589a-709f-16cc-69bf7df1d36c");
         /// <summary>Agent nodding yes</summary>
-        public readonly static UUID YES = new UUID("15dd911d-be82-2856-26db-27659b142875");
+        public static readonly UUID YES = new UUID("15dd911d-be82-2856-26db-27659b142875");
         /// <summary>Agent nodding yes with happy face</summary>
-        public readonly static UUID YES_HAPPY = new UUID("b8c8b2a3-9008-1771-3bfc-90924955ab2d");
+        public static readonly UUID YES_HAPPY = new UUID("b8c8b2a3-9008-1771-3bfc-90924955ab2d");
         /// <summary>Agent floating with legs and arms crossed</summary>
-        public readonly static UUID YOGA_FLOAT = new UUID("42ecd00b-9947-a97c-400a-bbc9174c7aeb");
+        public static readonly UUID YOGA_FLOAT = new UUID("42ecd00b-9947-a97c-400a-bbc9174c7aeb");
 
         /// <summary>
-        /// A dictionary containing all pre-defined animations
+        /// An immutable dictionary containing all pre-defined animations
         /// </summary>
-        /// <returns>A dictionary containing the pre-defined animations, 
+        /// <returns>An immutable dictionary containing the pre-defined animations, 
         /// where the key is the animations ID, and the value is a string
         /// containing a name to identify the purpose of the animation</returns>
-        public static Dictionary<UUID, string> ToDictionary()
+        public static ImmutableDictionary<UUID, string> ToDictionary()
         {
-            Dictionary<UUID, string> dict = new Dictionary<UUID, string>();
+            var builder = ImmutableDictionary.CreateBuilder<UUID, string>();
+
             Type type = typeof(Animations);
             foreach (FieldInfo field in type.GetFields(BindingFlags.Public | BindingFlags.Static))
             {
-                dict.Add((UUID)field.GetValue(type), field.Name);
+                builder.Add((UUID)field.GetValue(type), field.Name);
             }
-            return dict;
+            return builder.ToImmutable();
         }
     }
 }
diff --git a/LibreMetaverse/PacketDecoder.cs b/LibreMetaverse/PacketDecoder.cs
index c92ce76a..d97693a7 100644
--- a/LibreMetaverse/PacketDecoder.cs
+++ b/LibreMetaverse/PacketDecoder.cs
@@ -26,6 +26,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Reflection;
 using System.Text;
 
@@ -1424,7 +1425,7 @@ namespace OpenMetaverse.Packets
         private static string DecodeAnimToConst(string fieldName, object fieldData)
         {
             string animConst = "UUID";
-            Dictionary<UUID, string> animsDict = Animations.ToDictionary();
+            ImmutableDictionary<UUID, string> animsDict = Animations.ToDictionary();
             if (animsDict.ContainsKey((UUID) fieldData))
                 animConst = animsDict[(UUID) fieldData];
             return $"{fieldName,30}: {fieldData,-40} [{animConst}]";
@@ -1753,4 +1754,4 @@ namespace OpenMetaverse.Packets
             return result.ToString();
         }
     }
-}
\ No newline at end of file
+}
diff --git a/Programs/examples/TestClient/Commands/Agent/PlayAnimationCommand.cs b/Programs/examples/TestClient/Commands/Agent/PlayAnimationCommand.cs
index 07460247..aa211298 100644
--- a/Programs/examples/TestClient/Commands/Agent/PlayAnimationCommand.cs
+++ b/Programs/examples/TestClient/Commands/Agent/PlayAnimationCommand.cs
@@ -1,12 +1,13 @@
 using System;
 using System.Text;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 
 namespace OpenMetaverse.TestClient
 {
     public class PlayAnimationCommand : Command
     {        
-        private Dictionary<UUID, string> m_BuiltInAnimations = new Dictionary<UUID, string>(Animations.ToDictionary());
+        private readonly ImmutableDictionary<UUID, string> m_BuiltInAnimations = Animations.ToDictionary();
         public PlayAnimationCommand(TestClient testClient)
         {
             Name = "play";