From the Straight Dope.
Back when Cuba was under Batista and still a wretched hive of scum and villainy for depraved Americans to get their kicks, there was a nightclub performer, as well-known as he was well-endowed, who went by the moniker of "Superman" and specialised in live sex shows. He gets a fair bit of mention in the literature of the period, including Graham Greene's Our Man In Havana.