Prior to Letterman's joining DreamWorks Animation, he directed the short film Los Gringos, which was accepted at 2000's Sundance Film Festival.
He is known for directing Monsters vs. Aliens (2009) and Shark Tale which he received a nomination for the Annie Award for Writing in a Feature Production on the latter.
In 2010 Letterman directed the live-action film Gulliver's Travels, starring Jack Black in the lead role.
