AceShowbiz -

Now there is no doubt that "Tropic Thunder" will be a Frat Pack movie with the coming of Jack Black as the funnyman has delightfully boarded the DreamWorks' comedic project to play a role opposite Ben Stiller.

Billed as one of the five actors stuck in a real war-like situation when filming a big-budget war flick, Black will portray an overweight gross-out comedian named Jeff "Fats" Portnoy who is forced to kick his drug addiction during the shooting. Other two will be played by Robert Downey Jr. and Jay Baruchel with Stiller playing a character named Speedman.

Principal photography is scheduled to begin in July under the direction of Stiller who is set to helm from the script he himself wrote alongside Justin Theroux and Etan Cohen. Furthermore, the "Night at the Museum" star is also seating as producer together with Eric McLeod and Stuart Cornfeld, the latter having produced several of his movies like "Duplex" and "Starsky & Hutch."