A righthandman for a left hander
I'm lefthanded so I have a lefthandman instead of a righthandman.
1. In a wedding party, the next ranking groomsman after the best man. Often the X-factor at the bachelor party, and wedding reception responsible for turning things up a notch.
2. On a gang or team, the third ranking member. Often a wild card or tough guy.
"After winning and then losing 3 grand at the blackjack tables, I brought a couple strippers back to the bachelor party suite, and finished them both off. Just another night glorious night as a left hand man."
Historical examples: Mr. T in The A-Team, Zach Galifianakis in The Hangover, Dennis Rodman on the Chicago Bulls, Raphael from 'Teenage Mutant Ninja Turtles', Will Ferrel in 'Old School', Booger in 'Revenge of the Nerds',
The lowest ranking male in a gang bang with 3 or more guys and only one woman.
"Ron Jeremy wasn't always the king of the porn world. Rumor has it he was originally the left hand man in a few John Holmes movies (citation needed)."