Robert Thomas Letterman (born October 31, 1970) is an American film director and screenwriter who started with animation and moved on to live-action.　　He is known for directing Monsters vs. Aliens (2009) and co-directing Shark Tale (2004); he received a nomination for the Annie Award for Writing in a Feature Production on the latter.　　Prior to Letterman's joining DreamWorks Animation, he directed the short film Los Gringos, which was accepted at 2000's Sundance Film Festival.　　In 2010 Letterman directed the live-action film Gulliver's Travels, starring Jack Black in the lead role.