Klaus Heissler was once an East German Olympic ski-jumper until his brainwaves were switched with that of a goldfish in the 1986 Winter Olympics by the CIA to prevent him from winning the gold medal. It is unknown about the final fate of his original body, although it is presumed it might have expired (Klaus' original human body may have gone underwater and the goldfish brain was unaware that a human body needs air.) However, as for Klaus himself, he took up residency with the Smith family, where the CIA ordered Stan to have Klaus pose as their pet, a fact Klaus has still apparently not come to terms with.