Beelzebub is a transformation in The Binding of Isaac.
Obtained by acquiring any 3 items with the fly tag.
Grants Isaac flight and converts small enemy flies into Blue Flies.
Larger enemy flies such as Boom Flies, Pooters, Suckers, Moters, will become permanently charmed and follow you between rooms.
This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this transformation for the previous Repentance version, check this page instead.