Beelzebub

Beelzebub (beelzebuth/beelzebul) is a Philistine god mentioned as a demon in the Torah, the Bible, and several famous medieval occult texts including the Grand Grimoire/Red Dragon & Grimoiruim Verum.
He is usually listed as one of the three Lords of Hell, or unholy trinity, alongside Lucifer and Astaroth.

Beelzebub loosely translates to the lord of flies, and is commonly associated with insects, pride, gluttony and decay.

Beelzebub's inclusions in the books mentioned above generally don't have any illustrations, and he's not a common character in occult related movies, games, or other media,so there aren't many depictions of him floating around out there.