I rewatched the Iggy Pop episode of DS9 ("The Magnificent Ferengi") last night and I am convinced this was an all-time great piece of stunt-casting. First off, the sheer shock of "that's Iggy Pop, the guy famous for performing bare-chested and rolling around in broken glass on stage, in fucking Star Trek" is funny in and of itself. But he's also a terrible actor with a baffling approach to line delivery, and yet it fits so well with the comedic tone of the episode that it loops back in on itself and becomes a genius performance.
Just look at this, at the way he says "Not really, I was cloned":
