EXCLUSIVE: Relativity has filled out the cast of the untitled heist comedy formerly known as Loomis Fargo, from Napoleon Dynamite helmer Jared Hess. Zach Galifianakis stars as David, a simple armored car guard who takes the fall for a $20 million heist. He goes on the lam from the authorities while tracking double-crossers Steve (Owen Wilson) and Kelly (Kristen Wiig) and the gang of criminals who betrayed him as they blow the loot on ridiculous luxuries.

Ken Marino, who stars in NBC’s upcoming fall sitcom Marry Me, has been cast as Doug Jeffcoat, the rich and uptight neighbor who doesn’t like Steve and his friends degrading the wealthy neighborhood they’ve moved into. Saturday Night Live standout Kate McKinnon is set to play Galifianakis’ ball-busting fiancé. She’s joined by SNL writer Leslie Jones, who will play the detective on the thieves’ trail. The pic’s SNL roots are strong with Lorne Michaels producing; SNL and Up All Night scribe Emily Spivey penned the original script before Chris Bowman and Hubbel Palmer were brought on to rewrite.

It’s Always Sunny In Philadelphia‘s Mary Elizabeth Ellis will play Michelle, Steve’s cunning and gold-digging wife. Rounding out the cast are Devin Ratray, who lent his comic chops to last year’s Oscar nominated Nebraska and this year’s acclaimed revenge thriller Blue Ruin, and comedian Ross Kimball. The pair will play Steve’s loyal henchmen Runny and Eric.

The pic marks Jared Hess’s fifth feature after Sundance breakout Napoleon Dynamite, Nacho Libre, Gentleman Broncos, and the upcoming Bible-thumping comedy Don Verdean starring Sam Rockwell and Jemaine Clement. Michaels and John Goldwyn are producing the project, while Don Verdean co-star Danny McBride is exec producing alongside Jody Hill, Kevin Messick, Erin David, Ryan Kavanaugh, and Tucker Tooley. Brett Dahl is overseeing for the studio. Relativity’s already set high hopes for the comedy, which will compete next summer against Universal’s NWA biopic Straight Outta Compton in the August 14, 2015 slot.

Marino is repped by Paradigm and Principato-Young Entertainment. McKinnon is repped by UTA and Principato-Young. Ellis is repped by CAA and Evolution Entertainment. Jones is repped by APA and Integral Entertainment. Ratray is repped by Don Buchwald & Associates. Kimball is repped by UTA and Principato-Young.