Honourable Mention: Handsome Pete - Bart the Fink
Handsome Pete doesn't quite make the list unfortunately, because he has actually turned up a few times and thus breaks the rule. However, his first appearance in 'Bart the Fink' certainly fits the criteria - while looking for the supposedly dead Krusty the Clown, Bart partially inflates a balloon with the beloved clown's face on it and asks the Sea Captain if he has seen him. However, as the balloon is not fully inflated and as such Krusty's image is distorted, the Sea Captain assumes Bart is talking about Handsome Pete - the clown-faced, musical dwarf that plays sea shanties for a nickel and bares more than a passing resemblance to Krusty. The interesting thing about Handsome Pete is his career choice - you'd think that, given Krusty's popularity across all of Springfield, there'd be some call for a miniature lookalike to attend parties or even the Clown Show itself (especially seeing as Krusty lookalikes are apparently so in demand that there's an entire college set up to train them). But no - Pete completely eschews his visual association with Krusty and instead chooses the life of a humble maritime musician, content to play his accordion on the docks and piers of Springfield Harbour. Fair play Pete.