Jabba the Hutt had a knack for keeping some of the most terrifying beasts in the galaxy by his side. Of particular note is the Rancor, one of the most famous "Star Wars" creatures of all time, and one of the scariest, to boot.
Rancors move about a little like a Tyrannosaurus rex, on thick hind legs, using their shorter forelegs to claw at anything in their way. They have a hulking head and a face that can be best described as ... squishy. Rancors also drool incessantly, meaning they are messy to keep around, even for a slovenly crook like Jabba.
These creatures aren't entirely savage or feral. Many sentient species domesticated rancors, sometimes for transportation and protection, or in Jabba's case, as attack animals in an arena. No matter how tame they may have appeared, rancors are always to be treated as hazardous to your health, otherwise they could lash out unpredictably at any moment.