Kevin Federline is ready for a fight.

The estranged husband of Britney Spears is scheduled to face World Wrestling Entertainment champion John Cena in the ring on New Year's Day in Miami – and is already talking like he's the winner.

"The real Kevin Federline never backs down from a challenge," Federline said Monday night at Washington, D.C.'s Verizon Center, where a WWE extravaganza was taking place, The Washington Post's "Reliable Source" column reports.

Federline, who earlier this fall signed with the WWE to appear in some staged fights and was even body slammed by Cena in October, was there to promote his New Year's Day face-off.

And though the rapper is poised to for an uphill battle with Spears over custody of the couple's two children – Sean Preston, 1, and Jayden James who was born Sept. 12 – the 28-year-old says he'll be the victor when he meets the 6,1", 240-lb. Cena in the ring.

"Make all your jokes, because New Year's Day I'm the one who is going to be laughing," Federline shouted to Monday's crowd – which, according to The Post, booed him, except for two women upfront who extended their hands.

He also had an announcement for his rival. "Oh yeah, Cena, my name is not K-Fed, it's Kevin Federline, *****, and I want some and I'm gonna get some."

Spears filed for divorce from Federline on Nov. 6 after two years of marriage. Both Spears and Federline have asked for sole custody of their two sons.