Cool Penguin (Japanese: バッドばつMaru) is a male cartoon character in the shape of a black penguin with a yellow beak and feet created by the Japanese company Sanrio. He was born on April 1, 1993.

Cool Penguin is the mascot of the 2006 World Basketball Championship. In Taiwan, it is usually translated as "cool penguin", while in Hong Kong, it is often called "XO boy", because Badtz Maru comes from batsu, which represents X, and maru, which represents O.