Beelzebub appears as a strikingly beautiful demon woman with an elegant yet curvaceous figure and olive skin. Her long wavy hair reaches her waist, purple in the novels and white in the anime, and her eyes are a vivid purple, changed to red in the anime. Dark gray horns with teal interiors emerge from her head, marking her as a demon.

Her clothing is both minimal and ornate. She wears a white shift beneath a wine purple corset-like vest, paired with a loose belt and a black miniskirt or loincloth with high slits. On her legs are thigh-high stockings beneath black and gold greaves trimmed with white fur, matching heeled boots, and gloves styled with fur and armor plating. A black cape with a wine red lining drapes behind her, tied at the neck with long ribbons. She also carries a fluffy white fringed fan, usually tucked into her cleavage. True to her title as the Lord of the Flies, she can transform into a housefly.

Despite her aloof and sometimes stern demeanor, Beelzebub is hardworking, reliable, and fundamentally kind, though she often expects compensation for her efforts. She has a soft spot for Azusa’s daughters, Falfa and Shalsha, and frequently brings them gifts as excuses to dote on them.

In her official duties, Beelzebub is calm, efficient, and intensely dedicated, capable of working for long hours at a steady and accurate pace. She expects the same discipline from her subordinates, Fatla and the scatterbrained Vania, and does not hesitate to reprimand mistakes.

Before the events of the story, Beelzebub served as a public employee for 1500 years, eventually rising to the position of Minister of Agriculture under Provat Pecora Allières. She is first introduced through Halkara, who believes she is being hunted for revenge after Beelzebub collapsed from drinking Nutri-Spirits. The incident, however, was a misunderstanding. Beelzebub had simply overworked herself while relying on the drink’s energy, not been poisoned by it. Once Azusa neutralized her with a protective barrier, Beelzebub clarified her intentions and demanded a stable supply of Nutri-Spirits, having grown dependent on the tonic.