Beelzebub

Transformations

Guppy	Beelzebub	Super Bum	Yes Mother?	Bob	Fun Guy	Leviathan	Conjoined
Spun	Seraphim	Oh Crap	Bookworm	Spider Baby	Adult	Stompy

Isaac turns into a giant humanoid fly and gains flight. While in this form, most types of enemy flies will automatically be converted into blue flies.

Requires any combination of three of the following items to be collected:

Active collectibles

Name	ID	Icon	Quote	Description
Jar of Flies	434		Gotta catch 'em all?	Every time Isaac kills an enemy, a fly will be added to the jar, up to a maximum of 20. Using the Jar of Flies will release all the flies that are currently in the jar as friendly blue flies that will damage enemies.

Passive collectibles

Name	ID	Icon	Quote	Description
???'s Only Friend	320		Controlled friend	Summons a big attack fly that can be controlled with the shooting direction-keys.
BBF	272		Big Beautiful Fly	Spawns a familiar that flies around the room like the Boom Fly and explodes on contact with an enemy. Respawns after ten seconds.
Best Bud	274		Sworn protector	When hit, summons a white attack fly similar to Distant Admiration for the current room.
Big Fan	279		Fat protector	Spawns a large orbital familiar that blocks enemy projectiles and deals slight contact damage to enemies.
Distant Admiration	57		Attack fly	A red attack fly circles further out than the Halo of Flies / Pretty Flies, but closer than Forever Alone. Deals more damage than Forever Alone.
Forever Alone	128		Attack fly	Spawns a blue attack fly that orbits a long distance from Isaac.
Halo of Flies	10		Projectile protection	Spawns two pretty fly familiars that block enemy shots and deal contact damage to enemies.
Hive Mind	248		Giant spiders and flies	Increases the size of blue spiders and blue flies and doubles the amount of damage they deal.
Infestation	148		They grow inside	1-3 blue flies randomly spawn every time Isaac gets hit.
Skatole	9		Fly love	All types of fly except Boom Fly and Red Boom Fly become passive and slowly move towards Isaac. Does not prevent contact damage.
Smart Fly	264		Revenge fly	After Isaac takes damage, this fly will do continuous touch damage to whatever enemy caused the damage until it is dead. The fly will then systematically attack 1 enemy at a time until the room is cleared.
The Mulligan	151		They grow inside	Tears have a 1/6 chance of spawning allied blue flies when they hit an enemy.
Friend Zone	364		Friendly fly	A white orbiting fly which deals 3 contact damage per tick to enemies. This familiar orbits Isaac at a middle length distance somewhere between Distant Admiration and Forever Alone.
Lost Fly	365		Lost protector	A familiar fly that moves in a straight line and attaches itself to the first obstacle or wall it comes into contact within each room. If any enemies walk into its path, it will do 7 contact damage per tick. If the obstacle it is attached to is destroyed then it will continue rolling in the direction it was previously traveling until it meets another wall or obstacle.
Obsessed Fan	426		Follows my every move...	A purple fly familiar that follows Isaac's movements on a 3 second delay and deals contact damage to enemies.
Papa Fly	430		Turret follower	A blue fly familiar follows Isaac's movements on a 3 second delay. Papa Fly will fire tears at nearby enemies.
Angry Fly	511		He's violent	Spawns a fly familiar that orbits around a random enemy and deals 5 damage per tick to enemies it comes in contact with.

Notes

• The player starts with this transformation in the Solar System challenge.

Unlockable Achievements

• 

  Lord of the Flies - Become Lord of the Flies.

• 

  Angry Fly - Become Beelzebub.

Trivia

• Beelzebub is the name of a Demonic fly who is known as "Lord of the flies" and is known as one of the 7 princes of hell. Beelzebub is also another name for the devil.
• In modern Catholic tradition, Beelzebub is regarded as one of the 7 princes of Hell; however, the origins of the name Beelzebub actually dates back to an early Jewish insult for worshippers of a Canaanite Deity Ba'al 'Lord', or Ba'al-Zvul 'Lord of the manor/dwelling', calling him Ba'al-Zvuv, 'Lord of the flies'.
  • The achievement 'Lord of the Flies' is a reference to this.

Seeds

 PC  W2DW TA79 (Allows Isaac to become Beelzebub in Caves XL. First two treasure rooms are Big Fan and Attack Fly, one of the treasure rooms in Caves XL is Halo of Flies)

 PC  9CM4 JDBL (Last fly item collected on Flooded Caves I)

 PC  B14A Q44Y (also contains four Guppy items)

 Switch  TF11 R19Z (first three floors treasure rooms contain smart fly, forever alone, and infestation)