Typical. You wait eleven years for a trailer and then four come along at once…

Pixar has released a quartet of ever-so-slightly-different teasers for Monsters University, the prequel to 2001’s Monsters Inc, which chronicles Mike and Sully’s time at college.

In the clip Sully (John Goodman) plays a prank on his slumbering pal Mike Wazowski, played by Billy Crystal, who mutters some improvised lines in his sleep. But apparently Crystal’s off-the-cuff murmurings were so funny the studio felt compelled to release a selection of takes.

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

You can see one version of the trailer below and the other three are embedded at Yahoo, iTunes and The Huffington Post.

The film’s Facebook page is currently inviting fans to vote for their favourite version of the trailer, with the winning line to be drawn up by a Pixar artist and shared with the page's fans. 

Monsters University is currently scheduled to be released in the UK on 12 July 2013.