While Stallone's career was in its infancy, he took tiny roles in a few movies. There was soft-core porno The Party at Kitty and Stud's (later re-released as Italian Stallion to cash in on Stallone's burgeoning fame), as well as No Place to Hide and Klute.
Sly had an uncredited cameo in Woody Allen's South American dictatorship comedy Bananas, as a thug on the subway. The pair would later appear together in Antz.
Tough Guy? In Bananas, Stallone was required to intimidate Woody Allen (which probably isn't the most difficult task in the world).