Hippo Mask - Cool Masks - Off the Wall Toys Hippo's are aggressive and territorial. Now is your chance to be something you would never be in real life. We ask kindly that you do not completely embrace your animla instincts. Aggression while wearing a hippo mask does not excuse your behavior. Cool Mask for the animal lover! Great for a halloween costume. Made exclusively for Off the Wall Toys. Bagged with illustrated Off the Walls tag. To ensure it's the real deal please look for the Off the Wall Toys label.