Mutants are a big threat to the human race in the series.
They are big, green and scaly, ugly and mean creatures, who serve as antagonists throughout the series.
The mutants are stated to have an unknown piece of "cheese" craddled inside their brains, which in-turn are inside of their gluteus maximus.
They are rarely referred to by their species name, Garlokians.
Their hearts are located in their head.