🐉 GlymeraMobCustomizer v1.2.0

Create fully custom mobs with any appearance, any AI, custom health, scale, speed, and invulnerability. Mix a Dragon look with Wolf behavior - anything goes!

Most actual version only working for Hytale stable 5 ! Don't miss my other exciting projects — take a look at GlymeraCraft's Profile Discord: https://discord.gg/s5NRFWfxgy

◆ What is GlymeraMobCustomizer? GlymeraMobCustomizer is a mob creation plugin for Hytale servers. It lets server operators define custom mobs in a simple JSON config - choosing appearance and AI independently from hundreds of available options. Want a tiny fire-breathing Dragon with Hawk AI? A giant immortal Cow that fights like a Trork Warrior? A speed-boosted Mouse? Just configure it, spawn it with a command, and it's in your world.

Mobs survive server restarts natively. Hytale saves them with all modifications applied. No tick manipulation, no custom entity system - just Hytale's built-in NPC framework with your custom stats on top.

◆ How It Works The plugin provides a JSON config where you define named mob entries. Each entry specifies six properties: appearance, AI behavior, health, scale, speed, and immortality. When you spawn a mob via /cm spawn <name>, the plugin:

1. Looks up the mob definition from the config
2. Spawns the NPC using Hytale's native NPCPlugin with the specified AI role
3. Overrides the appearance model if it differs from the AI role
4. Applies scale, health, speed, and invulnerability via reflection
5. The mob is placed 3 blocks in front of the player, facing the player's look direction

All modifications are applied immediately on spawn. Hytale persists the entity with its modified properties automatically.

▸ Key Concepts Appearance and AI are independent - The appearance field controls the visual model (what the mob looks like). The ai field controls the behavior (how the mob acts, moves, and attacks). Any appearance can be combined with any AI role. A Cow that fights like a Skeleton Scout? No problem.

Config-based design - All mobs are defined in a single JSON file. No coding required. Edit the config, reload with /cm reload, and spawn your creation.

Template slots - The default config includes 10 pre-built example mobs and 50 empty template slots ready to be filled in.

Reference file auto-generation - On every server start, the plugin generates a read this!.txt file listing all available appearance models and AI roles directly from the running server. No guessing which values are valid.

◆ Mob Properties Each custom mob entry in the config has six configurable properties:

▸ appearance The visual model of the mob. Determines what the mob looks like on screen - its mesh, textures, and animations. The plugin reads all available models from Hytale's ModelAsset registry on startup and lists them in read this!.txt. Examples: "Horse", "Dragon_Fire", "Cow", "Skeleton_Scout", "Kweebec_Sapling", "Spider", "Golem_Crystal_Earth".

▸ ai The behavior/AI role of the mob. Determines how the mob acts - its movement patterns, attack behavior, aggression, idle behavior, and combat style. The plugin reads all available roles from Hytale's NPCPlugin on startup. Abstract template roles (prefixed with Template_) are listed separately and are not spawnable. Examples: "Trork_Warrior", "Hawk", "Wolf_Black", "Horse", "Mouse".

▸ health Maximum hit points. Range: 1-10000. Default: 100. The mob spawns with full health equal to this value. Both current and maximum health are set via reflection on the EntityStatMap.

▸ scale Size multiplier. Range: 0.1-10.0. Default: 1.0 (normal size). A value of 2.0 makes the mob twice as large, 0.5 makes it half size. Applied via reflection on the Model scale field with a network sync flag to ensure all players see the correct size.

▸ speed Movement speed. Range: 0.1-50.0. Default: -1.0 (use the AI role's default speed). Normal walking speed is around 3.0, horses are around 10.0. Applied via reflection on the MotionControllerBase's maxHorizontalSpeed field.

▸ immortal Invulnerability toggle. Default: false. When set to true, the Invulnerable component is added to the entity, making it completely immune to all damage. Useful for decorative NPCs, quest givers, or permanent world inhabitants.

◆ Commands (OP Only) All commands require operator permissions (checked via PermissionsModule wildcard * permission). The base command is /cm.

/cm spawn <name> - Spawn a custom mob 3 blocks in front of the player. The name is the config key (e.g. battle_cow, mini_dragon). Case-insensitive.

/cm list - List all configured custom mobs with their appearance, AI, health, scale, and immortal status.

/cm remove <name> - Remove the nearest mob of that type. Finds the closest NPC with a matching AI role name and removes it from the world.

/cm removeall <name> - Remove all mobs of that type from all loaded chunks. Iterates every loaded chunk, collects matching NPCs by role name, and removes them.

/cm reload - Reload the config file and regenerate the reference file without a server restart. New mob definitions are available immediately for spawning.

Typing /cm without arguments shows the help menu with all available subcommands.

◆ Configuration On first start, a config file is automatically created at: mods/Glymera_GlymeraMobCustomizer/config.json

The config contains a _README hint pointing to the reference file, followed by a mobs object with all mob definitions. Stop the server or use /cm reload after editing. The default config includes 10 example mobs and 50 empty template slots:

{
  "_README": "All available values for appearance and ai are listed in the file: read this!.txt",
  "mobs": {
    "giant_horse": {
      "appearance": "Horse",
      "ai": "Horse",
      "health": 500,
      "scale": 3.0,
      "speed": 12.0,
      "immortal": false
    },
    "battle_cow": {
      "appearance": "Cow",
      "ai": "Trork_Warrior",
      "health": 300,
      "scale": 2.0,
      "speed": 6.0,
      "immortal": false
    },
    "name_of_mob_1": {
      "appearance": "enter appearance - see read this!.txt",
      "ai": "enter ai - see read this!.txt",
      "health": 100,
      "scale": 1.0,
      "speed": -1.0,
      "immortal": false
    }
  }
}

◆ Pre-Built Example Mobs (10) The default config ships with 10 ready-to-spawn example mobs demonstrating different combinations:

◆ Reference File (read this!.txt) On every server start (and on /cm reload), the plugin automatically generates a reference file at: mods/Glymera_GlymeraMobCustomizer/read this!.txt

This file lists all available values for the appearance and ai fields, read directly from the running server's asset and NPC registries. It is divided into three sections:

Config Options - Explanation of all six mob properties with valid ranges and defaults. Appearances - All visual models from Hytale's ModelAsset registry (437+ models), sorted alphabetically. AI Roles - All NPC behavior roles from Hytale's NPCPlugin, split into spawnable roles (888+) and abstract templates (not spawnable, prefixed with Template_).

The file is regenerated on every start, so it always reflects the current server state including any asset packs or mods that add new models or roles.

◆ Technical Details NPC spawning via NPCPlugin.spawnEntity() - uses Hytale's native NPC framework for entity creation, ensuring full compatibility with the entity system Appearance override via NPCEntity.setAppearance() - only applied when appearance differs from the AI role, avoiding unnecessary operations Scale via reflection on Model.scale + ModelComponent network sync flag - ensures all connected clients see the correct size immediately Health via reflection on EntityStatValue (value + max fields) + EntityStatMap.setStatValue() - sets both current and maximum health Speed via reflection on MotionControllerBase.maxHorizontalSpeed - modifies the active motion controller of the NPC's role Invulnerability via Invulnerable component (ECS) - uses Hytale's built-in invulnerability system Spawn position calculated from player yaw - mob appears 3 blocks in front of the player using sine/cosine on the yaw angle Block operations deferred to world thread via world.execute() - all entity modifications and removals are thread-safe Mob removal by role name matching - iterates chunk-level NPC components via store.forEachChunk() OP permission check via PermissionsModule wildcard (*) - all commands are operator-only Reflection fields cached on startup - ModelComponent, MotionControllerBase, and EntityStatValue fields are resolved once and reused

◆ Server Log Output Example log messages:

[GlymeraMobCustomizer] Config loaded: 60 custom mobs.
[GlymeraMobCustomizer] Health stat index: 3
[GlymeraMobCustomizer] Reflection fields cached successfully.
[GlymeraMobCustomizer] Reference file generated: .../read this!.txt (437 appearances, 888 roles)
[GlymeraMobCustomizer] GlymeraMobCustomizer v1.2.0 started!
[GlymeraMobCustomizer] Setup complete. 60 custom mobs configured.
[GlymeraMobCustomizer] GlymeraMobCustomizer stopped.

◆ Installation

1. Stop your Hytale server
2. Copy GlymeraMobCustomizer-1.2.0.jar into your server's mods/ folder
3. Start the server
4. The config and reference file will be created automatically
5. Check the server log for: [GlymeraMobCustomizer] GlymeraMobCustomizer v1.2.0 started!

server/
└── mods/
    └── GlymeraMobCustomizer-1.2.0.jar

No asset pack required. No dependencies. Just one JAR file.

◆ Summary Fully custom mobs - define appearance, AI, health, scale, speed, and immortality independently Mix and match - any visual model with any AI behavior, hundreds of options each 10 pre-built examples - ready to spawn and play with out of the box 50 template slots - empty config entries ready to be filled in Auto-generated reference file - all valid appearance and AI values listed on every server start Hot reload - edit config and apply changes with /cm reload, no server restart needed Persistent mobs - survive server restarts natively through Hytale's entity system Easy removal - remove individual mobs or all mobs of a type with simple commands OP-only commands - all commands require operator permissions Zero dependencies - one JAR, no asset pack required, no external libraries

◆ Support Having issues or questions? Leave a message here or visit our Discord!

Developed by GlymeraCraft

The GlymeraMobCustomizer Team