Ever wanted to make your own custom mob, like a duck that walks around, or a custom enderman boss with special attacks? Well, now you can!

Custom Entity API is a datapack that provides one with tools to create their own custom mob, using an invisible mob of their choice as the AI for walking, targetting, etc, and Animated Java as a custom model for the entity.

* Disclaimer! This tool requires knowledge of Blockbench, Animated Java, datapacks, and animation, all to at least a basic degree!

This tool is featured at Smithed Summit!

Custom Entity API is at Smithed Summit 2026, boothed beside Animated Java and Vanilla Ride Studios, and plans to return in the future!

See an interview with the creator!

Learn

You can find documentation for Custom Entity API here.

Features

Custom Entity API supports the following:

• Switching between a custom walk and idle animation
• Custom hurt animation and the red hurt tint vanilla mobs have
• Custom death animation that can extend past a regular mob's death time
• Custom attacks that roll with a chance to play while the mob is targetting something

And more tailored for boss-type custom entities:

• Three attack pools (close range, mid range, and far range)
• Phase transition animations
• Stats and attack pool adjustments based on current phase

Special Attacks

Custom Entity API mobs can have three special attack types:

💥 Heavy: This attack will put shields on cooldown for 3x the amount an axe would, and generally indicate an attack will deal a large amount of damage.

⚔️ Parryable: This attack will activate a special interaction entity hitbox that if hit during a short window, will stun the boss, allowing for easy reward damage.

🛡️ Reaction: This attack will activate a special interaction entity hitbox that if hit will punish you for trying to hit the boss.

These special attack types are all indicated by a tint and glow effect displayed on the Animated Java model before the attack plays or during a wind-up animation.

Other Useful Tools Included

CEAPI comes with a few useful tools:

• Commands to apply attributes to your mob, toggling movement and armor, most commonly used during boss attacks.
• A macro particle command to run a particle command that requires a block_state using the block below the execute position of the command.
• A command to apply entity motion to the underlying AI part of the CEAPI mob.

You can read more about these useful tools in the CEAPI documentation.

Future Plans

This project will attempt to update alongside Animated Java for compatibility and support for new features, as well as update with Minecraft releases as consistently as possible.

A massive rewrite is also in the works to move lots of data from the AI mob to command storage, which will drastically increase performance scaling with multiple CEAPI mobs.

Issue Tracker

Will be coming soon!

Credits

This project was made entirely by lolimtaco