Swelesourus is the boss in the volcano cavern, and the 3rd boss in the game. She is the mother of Swelesourus jr. and cares deeply for him. Swelesourus is the guardian of the Barbaros' Castle treasure map. She attacks by launching fire balls at Zack, whitch will kill him if he is hit. She will only attack if Zack makes her son cry, rings Wiki to much, or neglects her son, making him lonely. She apparently hates the sound of bells ringing.

 The lava rock on her head is vital for her to stay alive. If it goes out, she will die. Zack almost kills her by breaking a chadelier, filled with water, causing the water to fall on her head. She survived by going under the lava, whitch re ignieted her crest. She then, flew off with jr. into the lava.