By Jeff Labrecque
April 01, 2009 at 02:30 PM EDT

Comic actor Will Arnett (Arrested Development) and recent Oscar nominee Michael Shannon (Revolutionary Road) have joined Warner Bros.’ adaptation of the DC Comics’ Jonah Hex, according to The Hollywood Reporter. Josh Brolin is already aboard, starring as the titular Civil War-era bounty hunter, and John Malkovich and Megan Fox are also attached to director Jimmy Hayward’s film.

Arnett will play serious, as a Union soldier who recruits Hex to fight a Confederate army of the undead, and Shannon will be the ringleader of a bizarre gladiatorial circus.