1) Nathan Fillion
From one Joss Whedon favourite to another, we bet you didn’t know that Nathan Fillion turned up in one of the same films as fellow Buffy alum Denisof. The reason this is a safe bet is because, just like that actor, Fillion was also hidden under an impenetrable alien disguise.
In the film, he’s actually one of the inmates who threatens Peter Quill and the Guardians when they are doing time in space prison the Kyln. Fillion is the bulky, reptilian turquoise one. The actor was pretty much guaranteed a part in Guardians, of course, as he often plays a role in James Gunn’s films, like Super and Slither. In fact, he’s set to get to use his own face in Guardians of the Galaxy Vol.2 as Simon Williams (who becomes the superhero Wonder Man in the comics).