How to Find the Correct Mob ID for the Bad Mobs Config

Understand the section format

Each mob in the Bad Mobs config is identified by a namespaced ID in square brackets, such as [minecraft:zombie] for vanilla mobs or [some_mod:custom_mob] for modded ones. The part before the colon is the mod or namespace, and the part after is the entity name. You must match this exactly — a typo means the section won't apply.

Discover IDs for modded mobs

If you don't know a mob's ID, the easiest route is to let the mod generate the section for you. Install the mod, load a world so entity types register, then reopen the config file and search for the mob's name. Modded mobs appear with their own namespace, so a mob from another mod will look like [thatmod:mob_name] rather than minecraft:. You can also check the other mod's own documentation or its entity registry names if the section hasn't appeared.

Verify before relying on it

After editing, reload or restart and test by trying to trigger the spawn you blocked. If the mob still shows up, the ID is likely wrong or the section is missing. Copy the bracketed header exactly as it appears in the file rather than typing it from memory. Keeping a backup of the config before large edits makes it easy to revert a bad change.