G. I. Zapp Theme Singer

He exists for a few seconds inside a Futurama gag: the booming, unseen vocalist belting out the theme song for G.I. Zapp, the show's fictional macho action franchise. He isn't a character so much as a voice — brassy, self-serious, utterly committed to the bit — selling the parody straight.

The joke works because nobody plays it as a joke. John DiMaggio, already the show's resident growl, leans into full theme-song bombast with a straight face, and that sincerity is the punchline. It's a blink-and-you'll-miss-it bit that rewards rewatching purely for the commitment of the delivery.