Lords of Chaos

This adds several bosses.
First, it adds two demon-type mobs that can be summoned using summoning tables or items.
Second, it adds one golem-type mob. Golems are very strong and appear when you destroy blocks in structures in the taiga. Finally, it adds an underwater mob. Structures are generated in the deep sea and they spawn when you destroy blocks. To counter this, it adds a diving suit and a submarine. These bosses are no match for vanilla gear, so they are recommended for adventurers and battle junkies.