Credit: WireImage

Katy Perry made a total of 7 outfit changes as the host of the 2010 Teen Choice Awards last night. In a hilarious costume montage, Perry spoofed every classic high school stereotype—cheerleader, prom queen, geek (complete with headgear), goth and hippie chick—alongside her Glee co-hosts, Cory Monteith, Mark Salling, Kevin McHale and Chris Colfer. Click on the gallery below to see all of Perry's geek-to-chic costume changes at the 2010 Teen Choice Awards, airing tonight at 8pm EST on FOX.