The Secret Life of Walter Mitty trailer Wednesday, July 31, 2013 8:45 p.m. by Matt Z Walter Mitty, played by Ben Stiller, daydreams and lives out adventures that we all grew up daydreaming about living out ourselves: It's a really good teaser trailer. I like Stiller but I'm not big on Kristen Wiig. Everything she does seems forced to me. Patton Oswalt is in the movie but not featured in the trailer. Do yourselves a favor and rent the movie Big Fan . Oswalt shows a side you've never seen before and he's fantastic. I also love the musical artist featured in the trailer, Of Monsters and Men . Really talented group. Christmas day is the release date for Walter.