Lavagirl is a young warrior who protects Planet Drool and rules Earth's lava world. She has the power to wield and control lava as it is part of her body. She is also the sidekick of Sharkboy. She thinks of him as her best friend and even died saving Sharkboy's life but because of him she lived because he threw her into the volcano. Lava also is unaware of who she truly is and wants to learn more about herself, she gets frustrated at times because max made her out of lava. She is overall a really friendly and nice girl.
After braving several obstacles during the film, Lavagirl meets and rescues Lordoboy. After she chooses to reproduce with him to keep their species going, Lavagirl meets a quick death during labor.