The Vogon Captain in charge of overseeing the destruction of the Earth, Prostetnic Vogon Jeltz is sadistic and unpleasant to look at, even by Vogon standards.
"Prostetnic Vogon" may be a title, rather than part of his name, since during the second episode of the third radio series (Fit the Fourteenth), two other Prostetnic Vogons are heard from.