Who is Beelzebub, Leader of the demons?

Answer:

The Pharisees gave the name Beelzebub to the highest of the evil spirits, i.e. the demons Jesus uses to drive out evil spirits (Mark 3:22 par, cf. Matthew 10:25). There are three ways of writing the name: Beelzebul (the majority use, also written like this outside the New Testament), Beezebul and Beelzebub. Etymology and meaning are uncertain.