The Katastrophe brothers are secondary antagonists in the show, due to being Spite's lackeys. They are all rather dumb. They are:
Chaos: A bull/Minotaur type creature. likely the smartest of the three, if it's not Kalamity.
Calamity: A vulture. Seems to trade off the "Smart one" role with Khaos quite frequently.
Confusion: A lizard and the dumbest of the three (hence the name).
When they get wet, they morph together and become the Katastrophe monster. They can only return to normal when the "Plug" (a ponytail type thing on the back of the neck) is pulled and the water is drained.
EDIT: fixed the names