Doctor Gerbil is con-artist posing as a vacuum salesman. He is the antagonist in the episode Human Habitrail.
Personality
Developer of a variety of hygienic products, his belief in animal freedom led him to experiment on human subjects. The effects of the testing typically cause strange results, such as additional growths on the body or the applied area to explode. He is extremely narcissistic, proven by the self-dedicated theme park built in the elaborate series of tunnels in his underground home.