Dr. Gerbil is a minor villain in Courage the Cowardly Dog. He appears in the episode "Human Habitrail".
In the episode, he poses as a vaccuum cleaning doctor, and uses a vaccuum to suck up Muriel and Eustace. He then tells Courage that he'd been freed of his torment. He then puts them through all kinds of tests as an act of vengeance on humans for their mistreatment of animals. He later chases Courage in a waterboat, and falls off a waterfall to his apparent doom, later on it is revealed he survived.
Eustace Bagge | Katz | Le Quack | The Chicken from Outer Space | Weremole | Cajun Fox | Rat & Weasel | Mattress Demon | Freaky Fred | King Ramses | Goose God | The Queen of the Black Puddle | Benton Tarantella | Errol van Volkheim | Snowman | Fusilli | Basil | Dr. Gerbil | Mustafa al Bacterius | Alien Brain Visitor | Alien Brain Boss | Spirit of the Harvest Moon | Dr. Zalost | Mecha Courage | Velvet Vic | King Buffo | Tulip | Fishtionary | Stitch Sisters | Windmill Vandals | Big Bayou | Kitty | Mad Dog | Evil Empress | Cruel Veterinarian | Perfectionist | Jean Bon