Biscus begins as a thief in the magical world, snatching two powerful magical briefcases. His theft is interrupted by Lalabel, causing panic that inadvertently activates the briefcases' magic. Both are transported to the human world, with one briefcase lost in the transition.
Physically, Biscus is very fat, with brown hair reaching his neck and black eyes. Stranded in the human world, he partners with Ochiba, a greedy and unpleasant ramen stand owner sharing his selfish nature. Biscus also owns a grey cat reflecting his nasty and horrid personality.
As the primary antagonist, Biscus repeatedly uses his stolen magic to swindle humans, often through get-rich-quick schemes. He simultaneously pursues Lalabel's remaining briefcase to gain more power. His plans consistently fail due to Lalabel's interventions, cementing his role as a buffoonish and ineffectual villain. Despite his antagonism, he occasionally forms temporary alliances with Lalabel when situations demand cooperation, hinting at latent complexity.
His character arc culminates in the series finale. After a final confrontation with Lalabel, both magical briefcases lose their power and vanish, stripping Biscus of his magic and rendering him fully human. This transformation, coupled with exposure to human kindness, prompts his reformation. He abandons villainy, promises never to harm Lalabel or her friends again, and departs with Ochiba on a journey dedicated to self-discovery as ordinary humans.
The 15-minute film *Magical Girl Lalabel: The Sea Calls for a Summer Vacation* focuses on Lalabel's seaside activities without involving Biscus.