COOL, or Cool-kun as called by Zu-chan or Rine, is a penguin mascot for the Chiba Lotte Marines.
He is known for being very stuck up and rude at times, but also being known to burst into tears or show great emotion when the time is right. He is well known for his acrobatic routine, often challenging Doala or B.B. to somersault contests at rival games.
He and Mar-kun do not get along very well,even though they are friends.
- Cool is a more recent mascot and has not been around very long.
- Cool is another one of the few characters that do 'speak' during live shows.
- Cool refers to himself using the term 'ore-sama', a stuck up way to say 'me' or 'I' in Japanese.