Mugwug, known in the original Japanese version as Mabuse, is a character from the 1981 anime film The Sea Prince and the Fire Child. He is a large, jealous, and bullying Japanese giant salamander who serves as a secondary antagonist within the story. In the English adaptation, his name is changed to Mugwug.

His background ties him to the undersea kingdom, where he harbors ambitions of seizing power. He is depicted as cunning and manipulative, using deceptive tactics to achieve his goals. His main motivation is to obtain the Eye of Argon, a powerful artifact entrusted to the protagonist Sirius, believing that possessing it will allow him to become the king of the sea. He is also driven by personal grievances, having reportedly lost a loved one to Sirius’s father, which fuels his resentment.

In the narrative, Mugwug repeatedly attempts to intimidate Sirius and take the Eye by force, but Sirius easily overpowers him. After being humiliated, Mugwug becomes secretly observant, following Sirius and discovering his forbidden romance with Malta, the princess of fire. Later, he overhears the plan for Sirius and Malta to escape to a celestial star where fire and water can coexist, and he immediately sets off to inform King Glaucus in order to betray the lovers. His actions heighten the conflict and force the protagonists into a desperate race against time.

Mugwug’s role is that of a persistent, spiteful troublemaker who primarily acts out of envy and a desire for authority. He shows no loyalty to any side and is feared by both sea and fire inhabitants for his willingness to cause chaos. His notable abilities include his physical strength as a large salamander, as well as a talent for sorcery and manipulation, which he uses to sow discord and pursue his own interests. Over the course of the film, he remains unchanging in his antagonism, serving as a foil to the protagonists’ pure intentions.