A German, Balding, Middle Aged, Clown Looking, Homosexual, High Pitched Man in Makeup known to many as a singer and to others as a culmination of child predators
Blessed with a voice only capable to most men upon having their testicles slammed in a door exactly 47 times, Klaus was known for randomly hitting notes usually reserved for... well reacting to slamming ones testicles in a door 47 times. Mix this with an overall creepy German accent, techno beats, and giant plastic tuxedos, and you have a wonderful combination that baffles the mind.
In fact I'm pretty sure that's what it sounds like when lightning strikes you right on the tip of your penis.
David Bowie is an interesting fellow and so of course he's going to need interesting fellows to back him up. Klaus Nomi was one of them
He later went on to become one of Bowie's bodyguards along with Iggy Pop as seen here in an episode of The Venture Bros.