The disgustoids, just like every other living thing, are presented in all shapes and sizes, usually possessing hideous and disgusting monstrous appearances while some others have reptile-like traits or other animal features. Also, some or most disgustoids share traits that are very similar to those of humans, such as Gweelok having muscular human arms but with three fingers and Slog having a human-like nose and other human-like features. Most are hostile to humans, while others are no longer accepted and trusted by the Humans. A few of them are very harmless (this is due to them living at their homes underground and also underneath ).
It may just be a stereotype but most Disgustoids are seen to have a very care-free, destructive personality. Exceptions being The Fart and Dingle. In the Uncle Grandpa Pilot, the Disgustoids go insane, trashing the house, fighting Uncle Grandpa and Ham Sandwich.