Binding of Isaac: Rebirth Wiki

Transformations alter Isaac's appearance and grant him special abilities.

A transformation occurs when obtaining at least three different items from a particular set of items.
These collectibles always share a particular theme that corresponds with the transformation.

Transformation Sets[ | ]

ID Name Appearance Description
0 Guppy Guppy

(except in Repentance) Grants flight and spawns a Blue Fly each time a tear hits an enemy.
(in Repentance) Grants flight and adds a 66% chance to spawn a Blue Fly when a tear hits an enemy.

1 Beelzebub Beelzebub

Grants flight. Converts small enemy flies into Blue Flies. (in Repentance) Larger flies become friendly and follow Isaac between rooms.

2 (except in Rebirth) Fun Guy Fun Guy

+1 Red Heart Container.

3 (except in Rebirth) Seraphim Seraphim

Grants flight and gives +3 Soul HeartSoul Hearts.

4 (except in Rebirth) Bob Bob

Isaac leaves a trail of green poisonous creep as he walks that deals 6 damage per second.

5 (except in Rebirth) Spun Spun

Gives +2 damage and +0.15 speed, and spawns a random pill upon transformation.

6 (except in Rebirth) Yes Mother? Yes Mother?

Isaac gains a stationary knife that trails directly behind him. It synergizes like Collectible Mom's Knife iconMom's Knife would.

7 (except in Rebirth) Conjoined Conjoined

Adds two tumors that fire diagonally from Isaac's head. -0.3 Damage, -0.3 Tears.

8 (except in Rebirth) Leviathan Leviathan

Grants flight and gives +2 Black HeartBlack Hearts.

9 (except in Rebirth) Oh Crap Oh Crap

Whenever a pile of poop is destroyed, restores half of a red heart.

10 (in Afterbirth † and Repentance) Bookworm Bookworm

Roughly 25% of the time, Isaac shoots an extra tear, like Collectible 20 20 icon20/20.

11 (in Afterbirth † and Repentance) Adult Adult

+1 Red Heart container.

12 (in Afterbirth † and Repentance) Spider Baby Spider Baby

Spawns a spider familiar that applies random status effects to enemies it comes in contact with.

13 (in Afterbirth † and Repentance) Stompy Stompy

Taking damage has a chance to spawn rock waves. (in Repentance) Isaac can break obstacles by walking over them.

n/a (except in Rebirth) Super Bum Super Bum

Replaces Collectible Bum Friend iconBum Friend, Collectible Dark Bum iconDark Bum, and Collectible Key Bum iconKey Bum with Super Bum. This bum collects any of the other beggars' pickups, and offers twice the rewards.

Requirements[ | ]

  • Items only need to have been acquired once in order to count.
    • (except in Repentance) Duplicate items (like those acquired from (except in Rebirth)Collectible Diplopia iconDiplopia) do not count toward transformations when picked up. Only the first instance of an item Isaac owns will count.
    • (in Repentance) Duplicate items are all counted.
    • Activated collectibles (e.g. Collectible Guppy's Head iconGuppy's Head) can be picked up once and then swapped away with another without any loss to transformation progress.
  • (except in Repentance) Rerolling items with a dice room, the Collectible D4 iconD4, or the Collectible D100 iconD100 will not remove progress towards the transformation.
    • (in Repentance) The transformation will be lost if the items required are rerolled or otherwise lost, eg. Collectible Sacrificial Altar iconSacrificial Altar.
  • (except in Rebirth) Familiars gained from Collectible Cambion Conception iconCambion Conception or Collectible Immaculate Conception iconImmaculate Conception do not count towards transformation progress.
  • Trinkets do not count toward progress for any transformation, with the sole exception of (in Repentance)Kid's DrawingKid's Drawing that counts for Guppy transformation.
  • Pills only count toward Adult and Stompy, they do not count toward progress for any other transformation.
  • Characters that start with an item that counts towards a transformation do count as one of the three items needed for a transformation, such as Judas starting with The Book of Belial.
  • (in Repentance) When playing as Character Jacob and Esau iconJacob and Esau or Character Tainted Lazarus iconTainted Lazarus only the character that picks up an activated item first gets the progress for related transformations, however both characters in the set may undergo the same transformation if they both collect the remaining required set items left in the item pool.
  • (in Repentance) Character Tainted Isaac iconTainted Isaac will not lose a transformation nor progress towards it if he replaces an item that counts towards that transformation.

Notes[ | ]

  • Transformations can be combined, keeping the effects of all transformations with no effects overriding others.
  • Transforming into Beelzebub for the first time will unlock the Lord of the Flies achievement and (in Afterbirth † and Repentance)Collectible Angry Fly iconAngry Fly.
  • Since none of the Afterbirth transformations unlock an achievement or item, attaining them is not required for 100% completion of the game in terms of achievements. (except in Rebirth) However, this is only true if you unlocked Collectible Mom's Contacts iconMom's Contacts on Rebirth, as the Yes Mother? transformation will happen once you collect three Mom items on Afterbirth and Afterbirth †.
  • (except in Repentance) Many of the Afterbirth transformations override the charge animations of items such as Collectible Monstro's Lung iconMonstro's Lung and Collectible Brimstone iconBrimstone, potentially making them more difficult to use.
    • (in Afterbirth † and Repentance) There is now an option to show a charge bar that floats above Isaac.

Gallery[ | ]

Trivia[ | ]

  • There are two transformations in the base game, nine more in the Afterbirth DLC, and four more in the Afterbirth † DLC.
  • In the original The Binding of Isaac flash game, the transformation into Guppy was the only one available, making it chronologically the first.
    • The Eternal Edition of the original The Binding of Isaac game added another transformation that turned Isaac into an angel after gaining 7 heart containers from eternal hearts.
  • Rebirth introduced Beelzebub as the chronologically second transformation.
  • The original name for the Beelzebub transformation was Lord of the Flies.
  • The reason no new transformations have been added to Repentance is because Edmund and the dev team do not like them, as they view them as significant advantages gained only from being lucky enough to find specific items. This is why Guppy, the most powerful transformation, requires much more effort to get compared to a transformation like Spider Baby. If any new transformations were to be added, they would be purely visual.[1]

References[ | ]