The Vogon Captain in charge of overseeing the destruction of the Earth, Prostetnic Vogon Jeltz is sadistic, even by Vogon standards. When not shouting at or executing members of his own crew for insubordination, Jeltz enjoys torturing hitchhikers on board his ship by reading his poetry at them, then having them thrown out of an airlock into open space.

Physically, Jeltz is described as being unpleasant to look at, even for other Vogons. Given that Ford Prefect describes Vogons as having "as much sex appeal as a road accident", one can only imagine how much worse Jeltz must appear. This may explain his disposition.