"OUT OF STOCK" Whoop Monster Youth T-Shirt - White Description: Kids�heck even adults have this love/hate relationship with Monsters. And the majority of motocross riders/racers have the same type of love/hate relationship with whoops. Put these two together and you get the Whoop Monster. Scary but fun. Intimidating yet exhilarating. The Whoop Monster t-shirts are made of 100% cotton with Phthalate free ink, meaning it is ok if your kids like to chew on their t-shirts. Machine wash.