Binding of Isaac: Rebirth Wiki

This article is about the playable character. For other uses, see ??? (Disambiguation).

???, also known as the Blue Baby, is a character unlocked by defeating Boss Mom's Heart ingameMom's Heart ten times. He starts with three Soul HeartSoul Hearts, and his health meter is unique in that he cannot gain red heart containers. If an item would grant him a red heart container (including an empty one), it adds a Soul HeartSoul Heart instead. While he has no passive starting items, he does spawn in with Collectible The Poop iconThe Poop.

Notes[ | ]

  • Sleeping on a bed will give ??? three Soul HeartSoul Hearts.
  • Enemies who deal full hearts of damage can be very dangerous in the early floors of the game.
  • Collectible The Poop iconThe Poop - While not the most useful item - can allow ??? to cross small gaps by bombing the PoopPoop from the opposite side, much like one would for Rocks. Furthermore, in rooms with non-flying enemies that chase the player (except SpiderSpiders), the poop can be used in a corner of the room, making ??? untouchable and allowing the player to kill them without taking damage (if the player moves away from the pile of Poop generated, this will no longer work).
    • Other utilities to the poop includes generating pickups, repelling projectiles once per room (using The Poop will also activate the effect of Collectible The Bean iconThe Bean) and destroying retracted spikes/ Red PoopRed Poop, benefiting ???'s defensive playstyles.
  • (in Afterbirth † and Repentance) Bone HeartBone Hearts grant an empty Bone Heart upon pickup, but they cannot be refilled using Red Hearts.
  • (in Repentance) The amount of Soul HeartSoul Hearts it costs to purchase an item in Devil RoomDevil Room deals is equal to its Red Heart container cost, unlike other characters with no red health for whom it will always cost 3 soul hearts.
  • (in Repentance) ??? has an innate Lil LarvaLil Larva effect; destroying a poop while playing as him will spawn a Blue Fly.
    • A possibly unintended effect is that this stacks multiple ???'s in true coop. This means that, along with The Poop, the potential flies gained per room increases quadratically with players, with the formula simply being the amount of ???'s in game to the second power.

Item Interactions[ | ]

Positive[ | ]

  • (except in Repentance)Collectible Abaddon iconAbaddon costs three Soul Hearts and grants six Black Hearts, damage up, fear shot, and no negative effects to ???. Abaddon can be bought safely regardless of current health, because its price can be deducted from the acquired Black Hearts retroactively.
    • (in Repentance)Collectible Abaddon iconAbaddon will give 2 black hearts on pickup, essentially refunding the cost to obtain the item from a Devil Room.
  • Collectible D20 iconD20 and (in Repentance)Collectible GB Bug iconGB Bug can be used to reroll any red hearts that may drop into useful pickups.
  • Collectible Ankh iconAnkh is effectively a Collectible 1up! icon1up! for ???.
  • (in Afterbirth and Afterbirth †)Collectible Athame iconAthame can be used to produce black hearts upon taking damage.
  • Balls of Steel pills or V - The HierophantV - The Hierophant grant two soul hearts, both of which are more useful than normal HP up items.
  • The Rune of DagazRune of Dagaz grants one soul heart as well as lifting any curses.
  • (in Rebirth) The XI - StrengthXI - Strength card gives ??? a permanent soul heart.
  • Collectible Book of Revelations iconBook of Revelations grants ??? soul hearts.
  • Collectible Ceremonial Robes iconCeremonial Robes costs (except in Repentance) three (in Repentance) two Soul Hearts and grants three Black Hearts and damage up. Like Collectible Abaddon iconAbaddon, this item is always safe to take.
  • (except in Rebirth)Collectible Crown Of Light iconCrown Of Light will always activate when entering a room, but still deactivates after taking damage.
  • Collectible Mitre iconMitre and Daemon's TailDaemon's Tail replace useless Red Hearts with Soul and Black Hearts respectively.
  • Collectible Dark Bum iconDark Bum converts useless Red Hearts into Black Hearts and blue spiders.
  • Collectible Dead Cat iconDead Cat will set Soul Hearts to 1, but can be used to gain devil deals by sacrificing the extra lives.
  • (in Afterbirth † and Repentance)Dim BulbDim Bulb is able to be activated every room due to the single charge on Collectible The Poop iconThe Poop, providing a consistent stat boost.
  • Collectible Gimpy iconGimpy has a chance to spawn Soul Hearts when hit.
  • (in Afterbirth † and Repentance)Collectible Hallowed Ground iconHallowed Ground turns all Collectible The Poop iconThe Poop uses into holy poops.
  • Collectible Lazarus' Rags iconLazarus' Rags causes ??? to be resurrected as Character Lazarus Risen iconLazarus Risen when he dies, allowing the gathering of heart containers. Once this happens, however, you are no longer playing as ???, and therefore cannot get any of his achievements/unlocks. The same effect happens with the use of Collectible Judas' Shadow iconJudas' Shadow.
  • (in Afterbirth and Afterbirth †)Collectible Maw Of The Void iconMaw Of The Void can produce Black Hearts.
  • Collectible Midas' Touch iconMidas' Touch makes Collectible The Poop iconThe Poop create Golden PoopGolden Poop.
  • Monkey PawMonkey Paw will drop 3 Black Hearts when at half a heart, but must take damage for each one to spawn.
  • Petrified PoopPetrified Poop is useful early on to get more pickups from Collectible The Poop iconThe Poop every room.
  • Collectible The Polaroid iconThe Polaroid and Collectible The Negative iconThe Negative will always activate when taking damage.
  • Collectible The Relic iconThe Relic, which is generally useful, is especially useful to ??? as it spawns Soul Hearts.
  • Collectible Satanic Bible iconSatanic Bible generates Black Hearts.
    • (in Repentance) Using Satanic Bible now also causes boss items to turn into devil deals that cost hearts, which is often worth since Devil deal items are cheap and better than boss items.
  • (except in Rebirth)Collectible Serpent's Kiss iconSerpent's Kiss can produce Black Hearts by poisoning enemies.
    • (in Repentance) Serpent's Kiss now only produces Black Hearts from contact damage poison, making it slightly less useful for ???.
  • Collectible Squeezy iconSqueezy and (except in Rebirth)Collectible Mr. Dolly iconMr. Dolly increase ???'s tears and can grant Soul Hearts.
  • Collectible Whore of Babylon iconWhore of Babylon is always active.
  • (in Repentance)Collectible Birthright iconBirthright will double the effectiveness of HP upgrades, meaning ??? gains twice as many soul hearts as normal.
    • This can be exploited with Collectible Converter iconConverter to generate unlimited HP.
  • (in Repentance)Collectible Fortune Cookie iconFortune Cookie can give a soul heart upon use.
  • (in Repentance)Collectible IBS iconIBS spawns different kinds of poop, all of which spawn blue flies when ??? destroys them.
  • (in Repentance) Judas' TongueJudas' Tongue lowers the price of Soul Heart Devil deals.

Negative[ | ]

  • Items that directly add Red Hearts to the health bar, such as Collectible Yum Heart iconYum Heart, (in Repentance)Collectible Yuck Heart iconYuck Heart or full health pills, are useless. However Eternal HeartEternal Hearts still act as an extra half a heart and become a full soul heart at the end of the floor making Collectible Prayer Card iconPrayer Card viable.
  • Blood Donation MachineBlood Donation Machines and Devil BeggarDevil Beggars are riskier, as they deplete health that is harder to replenish.
  • (except in Repentance) Cursed SkullCursed Skull will automatically teleport ??? out of the room upon taking any damage, as he doesn't have any Red Hearts. This can be used to easily warp out of the Boss RushBoss Rush room, but is mostly an annoyance.
    • (in Repentance) Works only at half a soul heart.
  • (in Afterbirth and Afterbirth †)Collectible Glass Cannon iconGlass Cannon will bring ??? down to half a Soul Heart, and not give back any health upon leaving a room due to ???'s lack of Red Hearts. This item essentially takes away most of the player's health in exchange for a single high damage tear.
    • (in Repentance) This effect no longer applies in Repentance, making it a more viable choice. Even so, caution should be used, as taking damage will cause the next damage taken in the room to be two full soul hearts, making this especially risky for ???.
  • Collectible Guppy's Paw iconGuppy's Paw, since requiring Red Hearts to convert, would be a useless item to hold (but should still be picked up and swapped back to get credit towards the Guppy transformation).
  • Collectible Little C.H.A.D. iconLittle C.H.A.D. is useless unless paired with Collectible Dark Bum iconDark Bum or (in Repentance)Apple of SodomApple of Sodom, where it becomes very useful.

Unlockable Achievements[ | ]

Trivia[ | ]

  • ??? appears in the original Binding of Isaac.
    • ???'s unlock requirements in Rebirth are the same in the original Binding of Isaac.
  • The name "Blue Baby" had not appeared in the game itself until the Afterbirth expansion, with a co-op baby named as such.
    • Before Afterbirth, in the original Binding of Isaac, his true name would appear in Isaac's Last Will in parentheses. This detail was overlooked/removed in Rebirth.
  • ???'s common nickname, Blue Baby, is a reference to blue baby syndrome, in which a baby's skin complexion appears blue from a lack of oxygen in its blood due to a congenital heart defect.
  • Many of Edmund's older flash games from Newgrounds feature ??? and Collectible Brother Bobby iconBrother Bobby. ??? was Edmund's mascot from 1996-2002.
  • In several cutscenes, Isaac is depicted suffocating inside a chest. ??? is first seen inside an identical chest, and Boss ??? ingame??? is the follow up boss after Boss Isaac ingameIsaac. Blue skin tone is typically used to show suffocation, and X eyes imply that the character is either knocked out or deceased.
    • After death, the bowels of the deceased will loosen, causing them to defecate themselves. This is most likely the reason ??? starts with Collectible The Poop iconThe Poop.
  • Unlike many of the other characters, ??? does not appear in the Bible or any religious scripture. He is the first character with this distinction, and the only one to appear in the original Binding of Isaac - the second being Character The Lost iconThe Lost in Rebirth, third being Character Keeper iconKeeper in Afterbirth and fourth being Character The Forgotten iconThe Forgotten in Afterbirth+.
  • The Collectible Ankh iconAnkh will resurrect any character as ???, even before he is unlocked.
  • Although "Blue Baby" is considered an unofficial nickname for ???, the character is referred to by this name in some of the game's code. One example of this is the image file for the character, named character_006_bluebaby.
  • ???'s look originally came from Dead Baby Dressup!, one of Edmund McMillen's first Flash games.
  • ???'s starting health is listed as "-I" on the character selection screen.
  • As a secret character, ??? does not appear on the character select screen until unlocked.

Gallery[ | ]