Bring a sense of magic and wonder to your breakfast table as you sip on a big old mug of Dad’s Fastest Swimmers! These mugs are said to change color right before your eyes – having said this we have no idea if they will actually work. There is a very good chance that this is just a normal mug. We’d love if someone tested this for us as we spent all our money on inflatable pool toys and can’t afford to test it ourselves. Coming in 11oz and 15oz sizes, this mug is the perfect way to enjoy favorite warm holiday drinks in style!