But director James Gunn originally had something entirely different in mind — Stan Lee in a cage, as part of the Collector's museum, maybe flipping off Groot. Gunn filmed the scene with a double in the UK (pictured) and would've filmed / digitally replace with Lee later ("not quite as difficult as it sounds"). But it was not meant to be. Here's an excerpt from his Instagram post:

A couple of the guys at Marvel thought Stan Lee in a case was too broad of a joke in general, and that it took the audience out of the movie. I argued about it for a bit, but we ended up not keeping it in the film. In a pretty typical case of Internet-journalism-telephone, articles online yesterday said that Disney forbade the scene because of standards. However, that's incorrect — no one at Disney ever even saw the scene, and it was cut solely for creative reasons.

It would've given Howard the Duck someone to talk to.