Thundercat is the name Stan gives to his second wife in the episodes "Stan of Arabia: Part 1" and "Stan of Arabia: Part 2" as he can't pronounce her proper name. She fights with Francine for Stan's affection on several occasions. She has also, according to Stan, been a better wife because she scored more points. Thundercat also has a daughter Rebecca.
Thundercat is voiced by Paget Brewster.