8x157 - Late Show with David Letterman

Mailbag: "Have you ever seen the Monkey Man?" Dave introduces the Monkey Man, who as any keen-eyed viewer can attest, is actually Gerard Mulligan in disguise. Monkey Man shows us a clip what is supposed to be his footage of him wrecking havoc, but instead it's him superimposed on Shecky's "monkey washing the cat" stock footage. Afterward, Dave observes, "That's it. That's the lowest we've sunk... ever."