This mod adds a 1% chance to make any mob a Pinata mob and on killing this mob it will launch clones of itself everywhere. The chance and clone amount is configurable. Clones can't be a Pinata mob. You can also disable the mod completely from the config if needed.
If you want to summon these mobs trough commands then use this.
/summon minecraft:zombie ~ ~ ~ {ForgeCaps:{"pinatamobs:pinata":{Pinata:1b, PinataChecked:1b}}}
