A common term used in Super Smash Bros. Melee, where a player in a 2v2 match will play as Ganondorf and sit at the edge of a fight, repeatedly Ganon kicking (Down + B) enemies who are busy fighting his teammate.
Recently, this statement has been used out of context, when somebody comes out of the blue, usually in an argument, with a particularly hurtful insult against one of the opposing parties
"Wow, he's just Ganon kicking us when we aren't paying attention, so cheap."
"You're just mad because your not used the Riding the Ganondorf."
Out of Context
"I was arguing with Eric, and there were some people standing around hoping we would fight, and Dovas just randomly insulted by grandparents. He knows there dead, too."
"Damn mate, Riding the Ganondorf is never fun, what a fag."