David Karpagnon was a resident at a children's home after his parents had abandoned him. He had a dissociative personality disorder which caused him to think he was a DeathBorg 400 on a secret Earth based mission.
Thinking himself as Karpagnon the DeathBorg 400, he plotted to escape the house and destroy it including all of the occupants, with a specific hatred for Petrie. (PROSE: The Terror of the Umpty Ums)
The Confounding Case of the Planetary Prankster • The Pernicious Plots of the Big Game Hunter • The Dangerous Dilemma of the Dream Doorway • Assassin on the Railroads • The Curious Case of the Weirdling Woods
Some categorisation may be based upon conjecture. Real world information should not enter into this. Additionally, a character's role in the DWU can differ from the real world - their placement here is for categorisation.