Maniacal Laughter

Maniacal Laughter is one of Futurama's background lab-coat fixtures, a nameless-seeming scientist who turns up whenever Professor Farnsworth needs a chorus of colleagues to gawk at some new invention. His entire function is delivering a punchline of pure cackling after a discovery, seemingly delighted by science itself, or possibly just by the sound of his own voice.

He works because the show commits so hard to the bit: a single-purpose gag character who exists solely to laugh maniacally on cue, credited as though he were a regular. Maurice LaMarche's booming, theatrical cackle sells the joke every time, turning a background extra into a running punchline that rewards viewers who notice the credits.