MultiGolem

Each variant is created from a carved pumpkin and an iron golem recipe by placing one of the material blocks in the centre of the T-shape, and the new golem keeps the tier's behaviour. Lightning heals a variant instead of damaging it, and a variant that drops below 25% health gains attack resistance while losing speed, then releases a Slowness X pulse when it dies. Tiers can be set to ignore certain target types, which stops collateral damage to them. The iron golem recipe and the single copper block recipe for the Copper Golem stay as vanilla has them.

MultiGolem is a server-side feature set that vanilla clients can join, and players with the mod installed see custom textures for each variant while vanilla clients still see regular iron golems. Server owners can control who creates a golem, who uses the marked spawn eggs and who may configure spawners, through LuckPerms-compatible permission nodes. Without a permissions plugin denying access, existing servers keep their current behaviour. The mod requires Fabric API and is released under the MIT License, and it is open source with its source code and issue tracker public.