Green Lady Monsters Inc

The nearly identical promos feature teenage Sully and Mike and their monster friends 'letting their fur down' at college before they have to work at Monsters, Inc.

Blue-haired Sully, voiced by John Goodman, is seen playing a prank on a sleeping Mike (Billy Crystal), who mutters a different sentence in each trailer.

Clutching a tube of glue, Sully sticks reflective panels on his circular friend, so he ends up looking like a disco ball.

Playing a prank: Sully can't stop laughing as he pulls out some glue

Given the disco soundtrack and the fact that his classmates start dancing around Mike once he storms out of his room, its safe to assume to trailer is probably set in the Seventies.

He is unaware of his new body art, fuming: 'If you're going to prank someone, at least you can do is think of something clever.'

Voicing the trailer, Crystal had so many ideas, producers decided to release four slightly different trailers.

Not impressed: Mike storms out of his dorm room to find a party going on in the hallway

In one promo, the sleep-talking monster says: 'I can't go to class, I'm not wearing any clothes, ' while in another he mutters: 'My homework ate my dog.'

In the third he says: 'My pony made the dean's list, ' while in the fourth he mumbles: 'Class president? Ha ha ha.'

Director Dan Scanlon said: 'Billy Crystal's an amazing comedic actor.

What's so funny? Mike doesn't realised he's been turned into a moving disco ball

'He gave us so much fun material, we decided to cut four slightly different versions of the trailer. We are so happy to have him back as Mike.'

Pixar are asking fans to vote for their favourite teaser trailer on the official Monsters University Facebook page.

The winner trailer will be drawn by a Pixar artist and shared exclusively with fans of the film.