Mods to recommend

Mowzie's Mobs adds a variety of fictional creatures to Minecraft, priding itself in unique AI, rich atmosphere, and fluid animations. Prove your might against new bosses and enemies and claim their magical abilities as your own.

🐉 Bring Souls-like Bosses into your world

A mod that improves Minecraft's lacklustre Wither boss

Adds various bosses with unique attacks and mechanics.