Shannon grew up in Orlando, Florida, on a steady diet of movies, comic books, and Saturday morning cartoons. He was introduced to acting through drama class and school plays, and then started performing professionally when he was 18 years old for Universal Parks & Resorts. That job took him from Orlando to London to Berlin, and then finally to Osaka, Japan. Shannon moved to Los Angeles in 2005, where he immediately began studying improvisation and sketch comedy at the Groundlings school, as well as ComedySportz Los Angeles. He scored his first television role on the acclaimed Fox drama House (2004). He continues to perform in film and television, and has recently started writing for animated television.