The Poop Biome

This mod adds several different additions to the game. They are all very cool.

The titular Poop Biome contains a brand new boss, along with a few extra structures. There is a treehouse where you can find a hint to fight another seperate boss. 

This seperate boss has a structure called the Withered Circle, a deadly building containing Spin Dylans, a secret treasure, and the key to summoning this brand new boss. Spin Dylan is a breed of Big Dylan and the Spiny Winny. 

This new boss drops the item which transports you to this new dimension, and it contains one last boss.

Among other things, there is an ice castle which you can rarely find in the tundra. This boss has a unique ranged weapon drop, and he likes to trick you!

I would spoil the fun, but the rest of the interesting things can be found in the mod by simply exploring the world. Good luck.