For Star Wars (any system, but preferably Fantasy Flight’s):

This pitch is for is an R2-series astromech droid starfighter pilot.

Yes, pilot. He flies an X-Wing or Y-Wing from the astromech socket. His organic partner was killed by a cockpit hit. He got the bird back to base at a time when the situation was so desperate that someone in authority let him keep flying. He’s steam-cleaned the gore out of the cockpit but otherwise left it gutted by the turbolaser hit (hey, not running life support means more power budget for shields). The starfighter is now painted in a monochrome version of the standard Rebel Alliance palette to make it look like an unmanned ghost fighter.

While the concept is wholly playable, the droid’s designation is the joke:

R2-F4.