Transformers: Optimus Prime Deluxe Kids Costume Our deluxe Optimus Prime kids costume includes a jumpsuit, chest piece, toy arm weapon and Optimus Prime mask. Our Optimus Prime kids costume comes in child sizes Large, Small, Medium. This Optimus Prime kids costume 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.