Wszystko jest w konfiguracji, wystarczy poczytać
schematics:
# These are the default settings applied to the schematics
defaults:
companion:
# Default island companion. Set schematic-specific companions in the schematic configuration
# Recommended are: COW, PIG, SHEEP, CHICKEN, VILLAGER, HORSE, IRON_GOLEM, OCELOT,
# RABBIT, WOLF, LLAMA or NOTHING. Default is COW.
# If you don't want a companion to spawn, set NOTHING.
type: COW