Jack Nicholson and Al Pacino have been added to the cast of madcap comedy Stuck on You - where Greg Kinnear and Matt Damon play twins conjoined at the head.

In the flick, one of the twins has a burning passion to get into showbusiness and drags his reluctant sibling along.

Cher is also in the movie, where she'll play a TV star who works with the twins, taking them trick-or-treating in once scene where the co-joined twins wear an octopus costume.

The film, to be made by Bobby and Peter Farrelly, will not make fun of the disabled, stress the brothers - also responsible for the controversial Gwyneth Paltrow flick Shallow Hal.

According to reports, the production team is also currently auditioning young actors with very big ears for a part in the flick.