Justin Bieber Adds More Cowbell To Willow Smith's Hair-Whipping

(Credit: Getty)

Last weekend, Willow Smith was in the UK opening for Justin Bieber on his "My World" tour, singing and dancing through another usual rousing performance of the killer song "Whip My Hair," in which Will and Jada's daughter lets those newly neon yellow braids do the talking (although that shouldn't downplay the fact that the girl's got pipes, too).

Anyway, Justin Bieber, a notorious prankster, shocked the screaming fans by appearing onstage not only to whip his hair back and forth too, but to provide more cowbell, borrowing the old joke from the "Saturday Night Live" sketch. Even if the joke went over the heads of the fans -- who very well may not have been alive when Will Ferrell cracked up a generation (not to mention his fellow cast members) -- Justin Bieber did comedy nerds proud.

Joined onstage by his manager and Swagger Coach (yes, really), The Biebs did an superb job of battling the elements -- Willow's solid, neon yellow braids, that is -- and reminding us that the kid still has an excellent sense of humor. He's already slaughtered on "SNL," so let's hope he makes a cameo sometime soon!