Justin Bieber is the guest host in the Season 9 opener, which finds the teen pop star pranking pals Taylor Swift, Rob Dyrdek and Sean Kingston.
Bam Margera pranks Tyler the Creator; Ronnie Ortiz-Magro; Tyler Posey.
Hayden Panettiere punks Dianna Agron, Zac Efron and Snooki.
Rapper Tyler, the Creator pranks his famous pals.
“Pretty Little Liars” star Lucy Hale pranks costar Ian Harding. Vanessa Hudgens and Josh Hutcherson are also pranked.
Nick Cannon welcomes the New Boyz to Hollywood; Ashley Tisdale; Demi Lavato.
Dax Shephard pranks Meta World Peace, Chloe Moritz and Lauren Conrad.
Miley Cyrus is the guest host. Prank victims include Kelly Osbourne, Khloe Kardashian and Liam Hemsworth.
Heather Morris pulls pranks on Joe Jonas, Cody Simpson and Emma Roberts.
Kellan Lutz is the guest host. Prank victims include Julianne Hough, Ashley Rickards and Aimee Teegarden.
Ashton Kutcher pranks Drake and Kim Kardashian.
Mac Miller is the guest host. Prank victims include T-Pain, Wiz Khalifa, Darrelle Revis and Neil Patrick Harris