Monsters on the Go Fitted Crib Sheet. Add a monster burst of color to your Monsters on the Go nursery with this sweet sheet featuring a fun pattern of Sully, Mike, and all of your favorite Monsters, Inc. friends in blues, greens, and oranges. This fitted crib sheet fits a standard size crib mattress 28″ x 52″. 100% polyester microfiber for a soft touch. Coordinates with a complete line of Monsters on the Go nursery bedding and decor.