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Isaac (boss)

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For information on the character, see Isaac.

Isaac is a new Boss added with the Wrath of the Lamb DLC. He is the game's main character as the final, fixed boss of The Cathedral.


Phase 1

Isaac will appear lying down in the center of the room, crying on the floor. He shoots 12 high-velocity tears in a radial burst and will retaliate with streams of tears when hit.

Phase 2

At 66% of his health, a light will shine on Isaac, and he jumps from the ground. Isaac will then start shooting 4 large purple tears, which home slightly, in all directions. He will still retaliate with some tears when hit.

Phase 3

Triggered near 33% of Isaac's health. Isaac will grow angel wings, smile, and start floating. White beams will be randomly shot down from the sky (Similar to Crack The Sky and White Pony), Angel Babies will start spawning frequently (up to a maximum of 6), and the same homing projectiles from before will be shot in six directions at the same time. At this point, Isaac will no longer retaliate with tears when hit.


  • Using The Bible during or after the fight will instantly kill the player (Similar to ??? and Satan) unless they have The Wafer item, which will deal 1/2 heart damage instead.
  • Using items with a high fire rate (Such as Technology 2) is dangerous in this fight, as Isaac will retaliate with a very large amount of tears upon being hit, unless you have mom's contacts. This also applies to effects which apply damage rapidly, such as Mom's Knife.
  • Applying slow effects such as Little Gish or Spider Bite to Isaac will not affect the speed of his homing tears, but will slow all normal tears.
  • Activating Mom's Bra or triggering the special effect of Mom's Contacts will prevent Isaac from spawning enemies or attacking at all—including when damaged—for the duration of the effect.
  • Isaac cannot be damaged by the Crack The Sky light beams, or by his own. However, any Angel Babies in the fight can take a small amount of damage from his light beams.
  • It is possible to reduce Isaac to 0 health. If Isaac is on 0 hp, the wings and light will disappear, and Isaac will resume crying on the floor. No projectiles/beams of light will be used (just like when ??? (boss) is reduced to 0 hp). However, any angels spawned from the previous phase will still survive, and will continue to attack you.



  • If the player uses The Hourglass, Isaac will fire blood tears instead of the usual blue tears and purple homing tears.
  • If the player is killed by the light beams in the final stage of the battle, the Last Will will display a picture of War.


  • The third form is referenced in the DLC's trailer, which showed Isaac sprouting wings.
  • When in Phase 1, Isaac makes the same weeping noises as the Mulligan.
  • When Isaac was first added in the initial release of Wrath of the Lamb, his third form only consisted of the rays of light, except with a tremendous rate of firing.
  • The picture of Isaac on Isaac's Last Will is identical to that of the Mulligan, but without the bloated head.


Destruyendo -It lives- y -Isaac- en The Binding of Isaac02:22

Destruyendo -It lives- y -Isaac- en The Binding of Isaac

Isaac boss fight in 101:15

Isaac boss fight in 1.4 Petden

Isaac fight in 1.4

The Binding Of Isaac Isaac00:49

The Binding Of Isaac Isaac

Isaac vs Isaac Petden03:10

Isaac vs Isaac Petden

Isaac fight + Ending + Getting Dad's Key

Binding of Isaac Isaac (boss) under 30 seconds00:43

Binding of Isaac Isaac (boss) under 30 seconds

Basement Larry Jr.MonstroThe Duke of FliesGeminiStevenFamine
Cellar WidowPinThe Duke of FliesFamineGurdy Jr.The Blighted Ovum
The Caves FistulaPeepGurdyChubC.H.A.D.Pestilence
Catacombs The HuskThe HollowThe Blighted OvumThe Carrion QueenPeepPestilenceThe WretchedGurdy Jr.
The Depths LokiMonstro IIGishWarMom
Necropolis Mask of InfamyDaddy Long LegsThe Carrion QueenThe BloatLokiWarThe WretchedMom
The Womb ScolexBlastocystThe BloatDeathConquestDaddy Long LegsTriachnidTeratomaMom's HeartIt Lives
Utero TeratomaThe BloatDeathConquestDaddy Long LegsTriachnidLokiiMom's HeartIt Lives
Sheol The FallenSatan
Cathedral Isaac
The Chest ???
First to fifth and seventh level The FallenHeadless Horseman
Devil Room Krampus

Start a Discussion Discussions about Isaac (boss)

  • OMG!

    5 messages
    • wrote:Versed isn't a verb, "it's" suggests present tense while "was" is past tense, the second and third "it's" should be "its", ...
    • all i am seeing is a random run post, dont we have a page for that?
  • That's my (sad) history

    15 messages
    • dead cat is pretty inconvenient, as somebody who plays azazel the bob's brain item is a game-ender, though
    • Bobs brain Is maybe a game ender But it Is when you play the lost I call bobs brain a kamikaze Item Also on my list Are BBF and Fire mind

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