Leviathan

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 Lovecraftian horror, gains 2 black hearts, and gains flight after picking up three of these items.

Activated Collectibles

Name	ID	Icon	Quote	Description
The Nail	83		Temporary demon form	Adds one soul heart and allows the breaking of rocks and damaging enemies by simply walking over them. Increases damage and decreases speed. All effects except for the Soul Heart wear off upon leaving the room.

Passive Collectibles

Name	ID	Icon	Quote	Description
Abaddon	230		Evil + DMG up + fear shot	Increases damage and speed, removes all Red Heart containers, grants six Black Hearts, and adds a chance to shoot fear tears.
Brimstone	118		Blood laser barrage	Tears are replaced by a laser beam that pierces through all enemies and obstacles in its path and deals high damage. Can only be fired after a short charge-up period.
Pentagram	51		DMG up	Increases damage and increases the chance for a Devil or Angel Room to appear.
Spirit of the Night	159		Scary	Grants spectral tears and flight.
The Mark	79		DMG up	Increases Damage and Speed, plus adds one Soul Heart.
The Pact	80		DMG + Tears UP	Increases damage by 0.5, tears by 0.7 and grants two soul hearts upon pickup.
Maw of the Void	399		Consume thy enemy!	+1.0 Damage. Continuously firing for 2.5 seconds then releasing the fire button creates a black ring around Isaac that rapidly deals damage and can cause enemies to drop Black hearts.

Gallery

• 

  Concept art for Leviathan along with other transformations that would be implemented into the Afterbirth DLC, by Edmund McMillen. Note that "Sistanis" is an early name of this transformation concept.

Trivia

• This transformation is based on the biblical creature of the same name.
• This transformation was initially misspelled as "Levathian" in Afterbirth but has been fixed in Afterbirth+.