Optimus Prime Cartoon Classic Child Costume - Medium This Optimus Prime costume for kids includes a jumpsuit and Optimus Prime mask. This Optimus Prime costume for kids comes in child sizes Medium, Small. This Optimus Prime costume for kids is an officially licensed Transformers costume. Please note: This item's color may vary due to inherent manufacturing variations or your computer monitor's color settings. The item you receive will be identical or substantially similar to the item pictured in this listing.