Transformers Masks for Kids 2 Pack Set - Bundle with Optimus Prime and Bumblebess Masks for Dress Up Pretend Play Plus Stickers, More | Transformers Costume Accessories. This Transformers dress up accessory set includes 2 Transformers masks: 1 Optimus Prime mask and 1 Bumblebee mask. Sure to be a hit with all Transformers fans, these masks are perfect to use as part of a Halloween costume or a costume party outfit. This Transformers mask 2 pack also includes bonus Transformers stickers, making the perfect gift set for your favorite Transformers enthusiast. Officially licensed Transformers masks for boys and girls alike. Includes a bonus Rex-Man door hanger.