He was voiced by Patton Oswalt.
Little has been revealed of Dementor's past or origin. He was apparently well-known as a supervillain before Drakken became a high-profile evil-doer; a running gag from the earlier seasons has others confuse Drakken for Dementor, much to the former's chagrin.
Dementor has something of a Napoleon complex, and is quick to anger. He generally follows a pattern of gloating, followed by exasperation, with a course of ranting to follow. He has an over-the-top Germanic accent.
He wears a distinctive black helmeted mask, brown trousers, and a red coat.
Dementor is a better scientist than Drakken, and he is also capable of stealing devices for his own needs. His henchmen are of superior quality, as well. Kim generally has to work hard to foil Dementor.
- His real surname may be "Demenz" (the German word for dementia), but as that was learned in a Dream (Rewriting History), it is unclear how reliable that information is.