For those of you not so well versed in the wide (and sometimes conflicting) myths of the world, the Doppelganger is a tangible double of a person, often of a more wicked inclination than the "original". Some mythology indicates that a Doppelganger is a portent of death or destruction; potentially yours, should the Doppelganger decide to usurp your life...
Two. Jareth's. Can't! Breathe! *explodes violently* On another note, can I borrow evil Jareth for awhile? (Or forever) *drools* I really don't know why I love really evil, sick, sadistic bastards. . . I think it has something to do with Crispin Freeman playing the voice of Alucard in Hellsing though. Aaaaaand there goes my brain. . .
I figured as much. Jareth may be gaudy, self-absorbed, arrogant, and the type to get jealous quickly, but he's not too outwardly malevolent. I can only imagine what his darker counterpart would be like, and I shiver slightly at the thought.