Beelzebub is a powerful demon, and one of the Seven Deadly Sins that rule over the Rings of Hell. She represents Gluttony, and controls the Gluttony Ring respectively. 
Beelzebub is a 'party animal', and loves to drink and have a good time. She encourages others to indulge in food and drink excessively, as long as it's done for the sake of having a fun party. Beelzebub is in a romantic relationship with a male hellhound demon named Vortex.