EXCLUSIVE: Mad Men star Jon Hamm has signed on to provide the lead voice (alongside Sandra Bullock) in Minions, the Universal Pictures/Illumination Entertainment spinoff of the Despicable Me franchise. Bullock is set to voice Scarlet Overkill, a stylish bad-ass super-villain who is (what else?) bent on world domination. Hamm will voice her husband, the inventor Herb Overkill. The 3D CG animated comedy has been set for release December 19, 2014.

At the same time, veteran animated feature film executive Tito Ortiz has returned to Chris Meledandri’s Illumination Entertainment in the position of VP Development. Ortiz was one of the original employees at Illumination when it opened its doors in 2007, serving as Director of Development until 2011, when he left the company to pursue opportunities in the music industry. Even during his hiatus, Ortiz stayed close to the company by assisting in development across multiple properties. In his new role, Ortiz will be involved in the development of new feature film projects, and has already started in that mission with the recently announced animated adaptation of Dr. Seuss’ How the Grinch Stole Christmas!, which will be directed by Pete Candeland.

Illumination and Universal next release Despicable Me 2 this summer, and then comes the spinoff with the adorable yellow henchmen, who got their start in 2010′s Despicable Me. This spinoff establishes that Minions have existed since the beginning of time, in service of history’s most ambitiously evil villains. Through their lovable ineptitude, Minions have managed to thwart and ultimately destroy all of those bad guys. This story picks up in the 1960s, before they hench-ed for Gru. With no more super-villains to serve, the Minions fall into a collective depression and three of them set out to seek a new evil master. They wind up at a villain convention, where they compete for the right to be henchmen for Scarlet Overkill, whose Audrey Hepburn-like high style appearance belies her world domination ambition and her aspirations to become the world’s first female super-villain. Minions will be produced by Illumination’s Meledandri and Janet Healy, and it will be directed by Pierre Coffin and Kyle Balda. Brian Lynch has written the screenplay, and Chris Renaud is executive producer.

Related: Despicablimp High-Hyping ‘Despicable Me 2′