Tales of the Beanworld
This is the Big Fish. We don't know much about it except that it's not a resident of the Beanworld, and has a taste for Notworms. It visited the Beanworld very early in its history. The story of its visit, and of the gift it gave to Mr. Spook, are told in issue 3, Big Fish Story.
The Big Fish shows up again in the ashcan Hungry?. In it, the Big Fish encounters Heyoka, who is on her way back to the Beanworld.