A speedster is a fictional character in superhero fiction, particularly comic books, whose primary power is the superhuman ability to perform physical and/or mental acts at impossibly high speeds. The most recognizable such superhero is the Flash. Some consider speedsters to be modern day descendants of the Greek deity Hermes and the Roman deity Mercury. Another notable speedster is Quicksilver who has been on The Avengers roster, and has had conflicts with the X-Men.