He was one of the Warlords sent by Don King to help Jillian Zamussels and Vinny Doombats in their attempt to stop Stanley the Tool from reaching the Kingdom of Faq. He was also part of Jillian's 'Royal Escort' back to Transylvito, along with Caesar Borgata, Vinny, and Dewy Tulips.
Real World References
"Leather" is an unusual first name, making it likely that this is a reference to the character of "Leather Tuscadero" in the series "Happy Days," particularly since Tuscadero is an Italian-sounding surname which would fit the Italian-American theme of Transylvito. Other Transylvito characters have made references to "Happy Days." The name is a pun for a leather bag (valise), such as one might keep a large amount of money in.