Custom mobs

Let's talk about real examples with entities and custom NBT.

Simple data

Make simple entities with NBT data.

Custom effects

Here an example to give glowing effect and levitation to entities using Rtag.

Entity entity = ...;

RtagEntity.edit(entity, tag -> {
    // Make it glow
    tag.set(true, "Glowing");

    // In case the entity its a mob or player it can receive potion effects
    // Note: This example only apply for Minecraft 1.20.2 or higher,
    //       so it's suggested to use Bukkit API to add potion effects
    //       (Or check MC wiki to see old tags and make your own method)
    Map<String, Object> effect = Map.of(
        "ambient", false,
        "amplifier", false,
        "duration", 200, // 10 seconds = 200 ticks
        "id", "minecraft:levitation",
        "show_icon", false,
        "show_particles", true,
        );
    tag.add(effect, "active_effects");
});

Attributes

Let's make a custom zombie that can pick up loot and deal more damage than zombies in Minecraft vanilla.

Zombie zombie = ...;

RtagEntity.edit(zombie, tag -> {
    // Make pickup loot
    tag.set(true, "CanPickUpLoot");
    // Make zombie deal 3.5 hearts of damage
    tag.setAttributeBase("generic.attackDamage", 3.5d);
});