Beelzebub

Beelzebub (ベルゼブブ) is one of the eight demon kings. He is the King of Insects (昆の王) and is affiliated with demons such as Chuchi.

Appearance
Beelzebub is one of the smallest amongst the Demon Kings, appearing around the height of a young child. His appearance is akin to antiquated royalty, dressed in a dark formal coat, puffy pantaloons and hosery and a high-collared cloak that appear similar to insect wings. His hair, most notably, extends into two antenna-like bulbs above his head.

Of One Cloth arc
Despite being a neutral faction amongst the Emperors and Demon Kings, Beelzebub appears amongst Mephisto's reinforcements in order to eliminated Satan who had manifested in Assiah.

Trivia

 * Beelzebub is a demon in Christian theology, though is thought to originate from other religions, particularly the Canaanite god, Baal.