Big Bad Pet
A Giant Mook that's usually an animal, or any non-human (commonly referred to as a "creature") for that matter, who is kept by the Big Bad as a pet.
Often too large or wild to be in the Big Bad's main quarters, the Pet is usually kept in a cage, cavern, dungeon, or any other secluded place. The Big Bad Pet's job is usually to guard the Big Bad's lair, or to viciously consume the hero once the latter is thrown in a pit of death. It's usually too dumb to actually be given orders, so it sort of serves as a Personal Mook for the villain.
To elaborate, Big Bad Pets are, well, big and bad. They usually are composed of dragons, snakes, sea monsters, giants, lions, bears, big hungry dogs, sharks, giant man-eating plants, and the like. They're the creature version of The Dragon, only usually much larger and of savage nature. Thus, they usually don't get that much character other than growling about to frighten the protagonists.
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