A race of monsters known as the Disgustoids are banished from society due to their unruly behavior and grotesque appearances. From their sentient and eponymous subterranean mountain fort, they unleash crazy stunts on the public. Their leader, a purple tusked and underwear-clad creature named Festro (voiced by Peter Browngardt), is a macho party animal willing to do anything to help out his group, even when his help is less than desired. Dingle (also voiced by Browngardt), a scrawny, blue dog-like monster who acts as their faithful pet, intelligible only to the group. Slog (voiced by Steve Little), a furred proboscis monkey-like monster, is likewise blindly loyal, but lacks critical judgment skills – the more hazardous something is, the more likely he will be to follow it. Gweelok (voiced by Paul Rugg), an acned ball of mucus, has a demanding attitude and an obsession with technology. The Fart (voiced by Pat Duke), a giant monster made of buttocks who farts when touched, is the most sensitive and level headed of the group. The show was based on the pilot for Uncle Grandpa.