Katy Perry's star-studded video for 'Last Friday Night (T.G.I.F.)' has officially hit the Internet! In the video, Perry portrays her super geeky alter ego Kathy Beth Terry who ends up turning into a '80s glam party animal, thanks to some help from her neighbor and fellow 'Friday' lover Rebecca Black.

The video kicks off with a cameo from 'Glee' star Darren Criss, as he barges into Kathy's room, which has been completely trashed from a Friday night romp. Before he exits, Criss screams, much to the displeasure of the hungover Kathy, "Best party of all time!"

Soon, Perry's character starts having flashbacks to the insanity that ensued at Rebecca Black's house party the night before. Originally, Ms. Terry went over to complain about the noise (she was trying to finish her Sudoku puzzle!), but was quickly accosted by Black and given a makeover, including the waxing of her mustache and the removal of her head gear.

Terry reenters the party looking fab in a skin-tight day glow dress with a teased hairdo. She starts getting all of the boys' attention at the party, especially that of Kevin McHale from 'Glee,' who fantasizes about having a medieval love affair with Kathy Beth Terry.

Throughout the rest of the video, the wonderfully random and comical cameos continue, with a rooftop guest appearance from "Uncle Kenny," played by saxophonist Kenny G. Also appearing in the video are house band Hanson, infamous '80s party playboy Cory Feldman (Terry's dad who cleverly asks her  why there is "a lost boy in [Kathy's] bed") and singer Debbie Gibson (Terry's mom).

Check out the hilarious video below, which premiered exclusively on Funny or Die.com. Party on, Katy!

Watch the Katy Perry 'Last Friday Night (T.G.I.F.)' Video