Call him the caped crusader... or just a complete jackass.

In any event, Kevin Federline swooped onstage for a hot performance at the KIIS-FM/West Hollywood Halloween carnival yesterday, as the rapping aspirant and father of four officially released his debut album, Playing With Fire.

Of his music, Mr. Britney Spears told People that he's ready to fight for what's his. Whatever that means. His quote: "It's something I believe in and I'm going to fight for it. I'm just another artist that's having to pay his dues."

Sure thing, dude. Why don't you give the people what they want (Jayden James pictures) and spare them what they don't want (your crappy CD)?