Justin Bieber knows how to show his fangs! The pop star joined forces with Cobra Starship at Sacramento's 107.9 Jingle Ball 2009 show, even making Cobra's signature fang sign with lead singer Gabe Saporta! The two even had a little showdown on stage!

"I was really looking forward to today's show because I've never met Justin Bieber before," Gabe announced. "I challenged him via Twitter to have a little dance-off today. And I'm not gonna lie, I was a little nervous but Justin broke his ankle, so I win by default!" Justin admitted that Gabe won, then decided to do an "epic drum solo" instead! "Thanks for showing me up!" Gabe said. "I just got smoked by a kid half my size!"

Check out the video below:

What do you think of the Cobra/Justin collab? Who do you think really won?

Photo: Courtesy of Atlantic Records