7. Eli Roth As Justin - Cabin Fever (2002) & 2001 Maniacs (2005)
Director Eli Roth, the world's foremost purveyor of the sub-genre known as "torture porn" proved that he wasn't above poking a little fun at himself when he played the amiable stoner Justin in his feature film debut, Cabin Fever. Justin stumbles upon the cabin dwelling gang at a camp fire while walking his dog, Dr. Mambo (who obtained his doctorate by being a dog). Justin coerces the ill-fated friends into letting him stay by offering up some of his weed before he abruptly leaves. Justin isn't seen again until much later in the film, when Paul stumbles upon his rotting, ravaged corpse. In 2005's 2001 Maniacs, Justin and Dr. Mambo appear once again, running into group of college kids that have run over his armadillo. Justin and Dr. Mambo are hitch-hiking to the woods where Cabin Fever takes place, with the cameo establishing a shared universe between the two movies. We even discover where Justin learns his "Faced!" catchphrase from. Scratch moded, indeed.
Fun Fact: The bowling alley manager is not portrayed by Eli Roth, but rather his brother, Adam.