Shuma is an old white whale and the arch-rival of the former-Khan, Hubbub. Shuma regularly raided Hubbub's city of Shattered Beams for fish, and one day, after becoming trapped in a cave, Hubbub and some whalers battled her, managing to deafen her, although Shuma killed the whalers and caused the loss of Hubbub's leg. Meanwhile, Quin a powerful Sea singer, used the Elder Horn, to force sea monsters to attack the city, and was successful in destroying the majority of it, leaving only two survivors: Hubbub, and the Old Man of the Sea. Since Hubbub was unable to take revenge on Quin, he took revenge on Shuma, whom he blamed for preventing him from being there and stopping it, and they have battled ever since.
Recently, Shuma set out to destroy New Heritage in an attempt to seek revenge on humanity, whom she regarded as responsible for the death of its family, which was sacrificed by Zu Zu under the orders of Quin. Hubbub set out to stop her, and proceeded to be eaten by her. In her belly, he used his "Sea Monster sense", which he had learnt he could use to use to talk to sea-creatures from the Old Man of the Sea, and convinced Shuma that Quin was the one she should seek revenge on, and in gratitude, she vomited Hubbub out. Since then, she and Hubbub have become good friends, as she enjoyed her battles with him.
- Shuma is most-likely a reference to the orca whale "Shamu".