These are Marvel Comics Avengers pajama pants! If you're a fan of Marvel Comics you'll love these top-notch pajama pants! They feature all of your favorite Avengers, Thor, Hulk, Captain America, Iron Man, and Black Widow in a comic book title design. Made of a cotton/poly blend that will keep you comfortable during the nights off of crime-fighting. For questions regarding sizing, please refer to size chart. These are the best!