Binding of Isaac: Rebirth Wiki
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Dr. Fetus is an unlockable passive item.

Effects[ | ]

  • Tears are replaced with BombBombs that explode approximately one second after being fired.
    • (in Rebirth) Each bomb deals 3 times the character's normal tear damage.
    • (in Afterbirth and Afterbirth †) Each bomb deals 5 times the character's normal tear damage plus a flat 30 damage. The flat 30 is not affected by damage multipliers.
    • (in Repentance) Dr. Fetus has two formulas for calculating the damage it does. At first, each bomb deals 10 times the character's normal tear damage. If the previous formula would lead to the bombs doing more than 60 damage, the bombs instead deal 5 times the character's normal tear damage plus a 30 flat damage. The flat 30 is not affected by damage multipliers.
    • Tears down: (except in Repentance) Tear Delay × 2.5 / (in Repentance)Fire Rate ÷ 2.5.
    • (except in Repentance) The range and shot speed stats both affect the velocity at which the bombs are fired out. Delay before the explosion is not affected by either.
      • (in Repentance) Bomb velocity formula has not been updated to account for the new range stat so it uses tear height for calculation (and not the actual range stat), resulting in the range stat effectively not working for Dr. Fetus with exceptions being Collectible Number One iconNumber One, Collectible Kidney Stone iconKidney Stone, Collectible Pluto iconPluto, and Collectible Inner Child iconInner Child's revive, which make velocity absurdly low. Shot speed still increases bomb velocity.
    • (in Repentance) Bombs grow larger or smaller with tear size modifiers and deal no knockback to each other.

Notes[ | ]

  • (except in Repentance) Dr. Fetus is a special item.
  • R U A Wizard? Does not affect Dr. Fetus.
  • Dr. Fetus overrides multiple tear effect items, but benefit from some ((in Rebirth) but not all) bomb-enhancing effects like Collectible Mr. Mega iconMr. Mega.
    • (except in Rebirth) Many more synergies have been added, and all passive bomb modifiers affect Dr. Fetus.
  • Dr. Fetus bombs deal half a heart of damage to Isaac. Other explosion damage is not affected.
    • Self-damage is increased to a full heart if the bomb would deal 85 damage or more. This includes effects from bomb modifiers, not just raw base damage.

Synergies[ | ]

  • (in Afterbirth † and Repentance)Collectible Apple! iconApple! / Collectible Euthanasia iconEuthanasia: Damage multiplier may be applied to the non-flat damage without a visual difference.
    • (except in Repentance) Euthanasia bombs do not retain the instant kill ability.
    • (in Repentance) Euthanasia bombs retain the instant kill ability.
  • (except in Rebirth)Bob's BladderBob's Bladder: Bombs from Dr. Fetus leave creep, allowing for extra damage.
  • Collectible Bobby-Bomb iconBobby-Bomb: Bombs home in on enemies.
  • (except in Rebirth)Collectible Bomber Boy iconBomber Boy: Bombs explode in a large cross-shaped pattern.
  • (in Repentance)Collectible Blood Bombs iconBlood Bombs: Bombs leave behind a pool of red creep.
  • (in Afterbirth and Afterbirth †)Collectible Brimstone iconBrimstone / Collectible Mom's Knife iconMom's Knife: Isaac continuously fires bombs while charging the beam/knife.
  • (in Repentance)Collectible Brimstone Bombs iconBrimstone Bombs: The activation rate of the Collectible Brimstone iconBrimstone lasers is random and dependent on Luck. The chance is 11% at 0 Luck, increasing by 3% per luck. This maximizes at 100% at 29.67 luck and minimizes at 0% at -3.67 luck.
  • Collectible Butt Bombs iconButt Bombs: Bombs inherit the Butt Bomb effects.
    • (in Repentance) The activation rate is random and dependent on luck. The chance is 20% at 0 Luck, increasing by 3% per luck. This maximizes at 100% at 26.67 luck and minimizes at 0% at -6.67 luck.
    • (except in Rebirth) Unlike normal Butt Bombs, this synergy cannot heal Boss Brownie ingameBrownie, (in Repentance) Boss Clog ingameClog, (in Repentance) Boss Colostomia ingameColostomia, Boss Dangle ingameDangle, or Boss Dingle ingameDingle. Both the explosion and the cloud effect deal full damage.
  • Poisonous Tears : Fires Collectible Bob's Curse iconBob's Curse bombs.
  • (except in Rebirth)Collectible Cricket's Body iconCricket's Body: The bombs split outwards into 4 tiny bombs, which detonate almost immediately.
    • The split bombs deal a flat (except in Repentance) 21 damage / (in Repentance) 35 damage.
    • (in Repentance) Increases range instead of decreasing it.
    • Cricket's Body + Collectible The Parasite iconThe Parasite: Bombs split outwards into 4 Cricket bombs and 2 Parasite bombs, which detonate and split a second time into the other type, for a total of 23 explosions.
  • (in Repentance)Collectible C Section iconC Section: C Section has priority. Does not apply Dr. Fetus' tears down. The fetuses drop small bombs when they touch an enemy. The bomb's damage follows Dr. Fetus' damage calculation, based on half of the fetuses damage. A fetus can drop only one bomb.
  • Dr. Fetus: Each additional copy of this item, such as from (except in Rebirth)Collectible Diplopia iconDiplopia / (in Afterbirth † and Repentance)Collectible Crooked Penny iconCrooked Penny, causes Isaac to fire one additional bomb in a side by side spread up to a maximum of 16 bombs. This maximum can’t be surpassed by other multi-shot effects such as 20/20.
  • (in Afterbirth † and Repentance)Collectible Eye of Belial iconEye of Belial: Bombs get piercing. No more further effect.
    • (in Repentance) Bombs deal 2.5x piercing damage.
  • Collectible Fire Mind iconFire Mind / (except in Rebirth)Collectible Hot Bombs iconHot Bombs: The bombs leave behind a fire that damages enemies on contact after exploding, and bombs themselves deal (in Afterbirth and Afterbirth †) 1 point of damage/(in Repentance) 16 damage on contact.
    • (in Repentance) For Hot Bombs, the activation rate of the fire is dependent on luck. The chance is 26% at 0 Luck, increasing by 6% per luck. This maximizes at 100% at 12.34 luck and minimizes at 0% at -4.34 luck.
    • (except in Repentance) Fire Mind + Collectible Cricket's Body iconCricket's Body / (except in Rebirth)Collectible Scatter Bombs iconScatter Bombs: The fire spawned from split bombs can damage Isaac.
  • (in Repentance)Collectible Ghost Bombs iconGhost Bombs: Bombs gain spectral and create ghosts when they explode. The activation rate of the ghosts is dependent on luck. The chance is 34% at 0 Luck, increasing by 8% per luck. This maximizes at 100% at 8.25 luck and minimizes at 0% at -4.25 luck.
  • Collectible Godhead iconGodhead: Does not give bombs the damaging aura, but does give them the homing effect.
  • (in Repentance) GuppyGuppy/Collectible The Mulligan iconThe Mulligan: Explosions can spawn flies.
  • (in Afterbirth † and Repentance)Collectible Haemolacria iconHaemolacria: Haemolacria has priority. Applies +10 Tear Delay after Haemolacria tears down, instead of Dr. Fetus tears down. The main tear is reminiscent of a bomb and scatters into 3-5 bombs that explode simultaneously. The split bombs deal half of Dr. Fetus' damage calculation based on the main tear's damage.
    • Haemolacria + Collectible Sad Bombs iconSad Bombs: Sad bombs from Haemolacria tears shoot 10 Haemolacria tears, which then scatters into bombs without Sad Bombs' property.
  • Collectible Ipecac iconIpecac: The bombs become Collectible Bob's Curse iconBob's Curse bombs. Isaac is immune to his bomb shots (not explosives or placed bombs). Shots will also explode immediately on impact with enemies, rocks, PoopPoops, angel statues, devil statues, or walls. Does not apply Ipecac's tears down.
    • (except in Repentance) The damage is massively increased, as the +40 damage from Ipecac is run through the damage multiplier of Dr. Fetus.
    • (in Repentance) The effect on damage becomes a flat +2 bonus instead of +40. Bombs leave behind a cloud of poison gas that will poison enemies in contact with it.
    • (except in Repentance) Ipecac + Collectible Cricket's Body iconCricket's Body / Collectible The Parasite iconThe Parasite / Collectible Polyphemus iconPolyphemus / Collectible Sad Bombs iconSad Bombs / (except in Rebirth)Collectible Scatter Bombs iconScatter Bombs: Isaac is immune to the main bomb shot, but not to the explosive shrapnel.
      • (in Repentance) Isaac is immune to the shrapnel bombs left by Cricket's Body, The Parasite, Polyphemus, and Scatter Bombs. Isaac is not immune to Ipecac shots from Sad Bombs.
    • Ipecac + Collectible Monstro's Lung iconMonstro's Lung: Isaac is no longer immune to his own bombs, and since they explode as soon as they make contact, it makes self-damage very likely. (in Repentance) The flat damage bonus is increased to +40.
    • Ipecac + (except in Rebirth)Collectible Tech X iconTech X: Isaac is immune to the main bomb shot, but not the explosions created by the laser ring.
  • (in Repentance)Collectible Little Horn iconLittle Horn: Black-tinted bombs can summon Big Horn's hand to instantly kill non-boss enemies or to deal damage against bosses.
  • (in Afterbirth and Afterbirth †)Collectible Monstro's Lung iconMonstro's Lung: Monstro's Lung has priority. Does not apply Dr. Fetus' tears down. Fires 6 bombs which detonate simultaneously.
    • (in Repentance) Monstro's Lung has priority. Does not apply Dr. Fetus' tears down. Fires 6 mini-bombs which detonate at different times.
    • Multi-shot effects add 1 bomb to the barrage, up to 21 bombs.
  • Collectible Mr. Mega iconMr. Mega: Adds 25 flat damage to bomb explosions.
    • (in Repentance) The bonus damage is only applied if the bombs are visually Mr. Mega bombs, which means items like Collectible Soy Milk iconSoy Milk won't get the bonus damage.
  • (except in Rebirth)Collectible Mysterious Liquid iconMysterious Liquid: Exploding bombs leave behind a large pool of creep.
  • (except in Rebirth)Collectible The Parasite iconThe Parasite: Upon exploding, bombs split into two other bombs, which explode almost immediately.
    • The split bombs deal a flat (except in Repentance) 24 damage/(in Repentance) 40 damage.
    • The Parasite + Collectible Cricket's Body iconCricket's Body: Bombs split outwards into 2 Parasite bombs and 4 Cricket bombs, which detonate and split a second time into the other type, for a total of 23 explosions.
  • (in Repentance) Piercing tears: Bombs deal 2.5x Isaac's damage to enemies when passing through them.
  • Poison tears: This is guaranteed by Collectible Bob's Curse iconBob's Curse, Collectible Ipecac iconIpecac, and Collectible Scorpio iconScorpio, and also has a chance to trigger from Collectible The Common Cold iconThe Common Cold, (in Afterbirth † and Repentance)Black ToothBlack Tooth, Pinky EyePinky Eye or (except in Rebirth)Collectible Serpent's Kiss iconSerpent's Kiss.
    • (in Repentance) Poison bombs leave behind a cloud of toxic gas that will poison enemies in contact with it aside from the main target.
  • Collectible Polyphemus iconPolyphemus: The bombs increase in size and do increased damage.
    • (except in Rebirth) The bombs become Collectible Mr. Mega iconMr. Mega bombs. After they detonate, they leave behind a regular-sized bomb that deals a flat (except in Repentance) 60 damage/(in Repentance) 100 damage, much like a standard bomb.
  • Collectible Proptosis iconProptosis: Distance penalty does not apply.
    • (except in Repentance) The non-flat damage for Dr. Fetus' damage calculation is doubled.
    • (in Repentance) The non-flat damage for Dr. Fetus' damage calculation is tripled.
  • Collectible Pyromaniac iconPyromaniac: Explosions heal Isaac, essentially making him invincible as long as he has at least one red heart container.
  • Collectible Remote Detonator iconRemote Detonator: The bombs can be detonated on command, making it easier to hit moving enemies. Unlike placed bombs, they will eventually detonate on their own.
  • (in Repentance)Collectible Rocket in a Jar iconRocket in a Jar: Shoots rockets.
    • Piercing tears: Rockets do not pierce through enemies. However, they deal both piercing damage and explosion damage on impact with an enemy.
    • Rocket in a Jar + Collectible Polyphemus iconPolyphemus: Rockets will “bounce” off of enemies, rocks, and walls, detonating twice. This is easily observable by firing parallel to a wall while moving towards it.
  • (except in Rebirth)Collectible Sad Bombs iconSad Bombs: Fires tears as normally placed Sad Bombs would.
    • (in Repentance) The activation rate is random and dependent on luck. The chance is 11% at 0 Luck, increasing by 3% per luck. This maximizes at 100% at 29.67 luck and minimizes at 0% at -3.67 luck.
  • (except in Rebirth)Collectible Scatter Bombs iconScatter Bombs: The bombs split into (except in Repentance) 2-4/(in Repentance) 4-5 tiny bombs. The bombs deal half damage of the bomb it came from.
    • (in Repentance) The activation rate is random and dependent on luck. The chance is 34% at 0 Luck, increasing by 8% per luck. This maximizes at 100% at 8.25 luck and minimizes at 0% at -4.25 luck.
  • (in Afterbirth and Afterbirth †)Collectible Technology iconTechnology: Both fire normally.
  • (except in Rebirth)Collectible Tech X iconTech X: Dr. Fetus has priority. The bombs have a laser ring around them.
  • Collectible Tough Love iconTough Love: Damage multiplier may be applied to the non-flat damage without a visual difference.
  • (in Repentance)Collectible Uranus iconUranus: The bombs freeze enemies upon killing them.

Interactions[ | ]

Overridden by Dr. Fetus:

Only stat effects are applied; otherwise overridden by Dr. Fetus:

Other interactions:

  • (except in Rebirth)Blasting CapBlasting Cap: Shot bombs cannot drop additional bombs.
  • (except in Repentance)Collectible Chocolate Milk iconChocolate Milk: The bombs can't be charged, but reduces Isaac's tear delay by 20%.
  • Collectible Epic Fetus iconEpic Fetus: Overrides Dr. Fetus.
  • (in Repentance)Collectible Explosivo iconExplosivo: The bombs have a chance of sticking to an enemy. These bombs have the same appearance as Collectible Sticky Bombs iconSticky Bombs, but do not spawn spiders or slowing white creep.
  • (in Repentance)Collectible Eye Sore iconEye Sore: When Isaac shoots, he has a chance to fire 1-3 additional bombs in random directions.
  • Character The Forgotten iconThe Forgotten/(in Repentance) Character Tainted Forgotten iconTainted Forgotten: A live bomb will spawn on top of The Forgotten when he starts charging his attack. The Forgotten will toss bombs after releasing the charge; airborne bombs deal 1.5x his damage if they collide with an enemy with enough speed. Max distance is obtained with minimal charge. If the bomb explodes while charging, a normal ranged bone attack happens after releasing it. The melee attack is unaffected.
  • (in Repentance)Collectible Immaculate Heart iconImmaculate Heart: Orbital tears do not become bombs.
  • (in Repentance) Collectible Kidney Stone iconKidney Stone / Collectible Number One iconNumber One / Collectible Pluto iconPluto / Collectible Inner Child iconInner Child's revive: The bombs lose almost all of their range, and cannot be improved by range ups. Shot speed and tear height ups can be used to mitigate this downside.
  • (except in Repentance)Collectible Kidney Stone iconKidney Stone: The range decrease applies, but since the tear falling speed stat doesn't affect Dr. Fetus' bombs, they spawn directly in front of Isaac, making self-damage very likely. The effect can be mitigated with range ups.
  • (in Repentance)Collectible Lead Pencil iconLead Pencil Every fifteenth shot will cause a barrage of short-ranged tears, which blocks the path of the bomb and can harm Isaac as the result.
  • Collectible The Ludovico Technique iconThe Ludovico Technique: The bomb can be controlled before exploding, similar to Collectible Epic Fetus iconEpic Fetus. Isaac does not shoot bombs while controlling it.
    • The Ludovico Technique + (in Repentance)Collectible Almond Milk iconAlmond Milk / Collectible Soy Milk iconSoy Milk: Since Isaac can't shoot bombs before they explode, this results in a damage down with no effective fire rate increase.
  • (in Repentance)Collectible Marked iconMarked: Isaac continuously fires bombs at the crosshair.
  • (in Rebirth)Collectible Monstro's Lung iconMonstro's Lung: Same effect as Collectible 20 20 icon20/20, except retains fire rate.
  • Collectible Mom's Eye iconMom's Eye: Grants a chance to shoot an extra bomb from the back of Isaac's head.
    • Mom's Eye + (in Repentance)Collectible Eye of the Occult iconEye of the Occult: Bombs that spawn from Mom's Eye will try to move to where you're shooting making it very difficult to not get hit by your own explosions.
  • (in Rebirth and Repentance)Collectible Mom's Knife iconMom's Knife: Overrides Dr. Fetus.
  • Collectible My Reflection iconMy Reflection: The bombs lose momentum and slide back towards Isaac, making self-damage very likely.
  • (in Afterbirth † and Repentance)Ouroboros WormOuroboros Worm: Does not affect the trajectory of the bombs. Turns some bombs into homing bombs, similar to Collectible Bobby-Bomb iconBobby-Bomb.
  • (in Repentance)Collectible Parasitoid iconParasitoid: Bomb explosions have a chance of leaving the slowing creep in a larger pool than egg sack tears, however the egg sack bombs can't spawn Blue Flies/Blue Spiders.
  • (except in Repentance) Piercing tears: The bombs pierce through enemies, which makes killing them more difficult.
  • (in Rebirth) Collectible Soy Milk iconSoy Milk: Rapidly shoots very low damage bombs. Can create a line of bombs which can knock each other back, which can be difficult to avoid taking damage from.
    • (in Afterbirth and Afterbirth †) Rapidly shoots medium damage bombs. Can create a line of bombs which can knock each other back, which can be difficult to avoid taking damage from.
    • (in Repentance) Rapidly shoots low damage mini-bombs. Bombs don't knock each other back.
  • Spectral tears: The bombs can pierce through the obstacles. If a bomb is fired inside an obstacle, the bomb collides against it, but not against others.
  • (in Repentance)Collectible Spirit Sword iconSpirit Sword: Overrides Dr. Fetus.
    • Spirit Sword + Collectible Haemolacria iconHaemolacria: The split bombs can appear from Spirit Sword's projectiles.
  • (except in Rebirth)Collectible Sticky Bombs iconSticky Bombs: The bombs stick to enemies ((except in Repentance) unless Isaac has piercing), but enemies killed by the bomb will not spawn Blue Spiders.
    • (in Repentance) The bombs always spawn slowing white creep after exploding.
  • (except in Rebirth)Collectible Tear Detonator iconTear Detonator: No effect on bombs.
  • (in Repentance) Tear height ups such as Tape WormTape Worm, Collectible Jupiter iconJupiter, Collectible Telepathy for Dummies iconTelepathy for Dummies, I - The MagicianI - The Magician, and Huge GrowthHuge Growth: Improves the effective range of the bombs.
  • (in Repentance)Collectible Technology 2 iconTechnology 2: The bombs are pushed forward by the laser.
  • (in Afterbirth † and Repentance)Collectible Technology Zero iconTechnology Zero: Dr. Fetus bombs do not generate electricity. Tears from other sources such as Collectible Sad Bombs iconSad Bombs can still generate electricity.
  • (except in Rebirth)Collectible The Wiz iconThe Wiz: Causes Isaac to fire two bombs instead of one in diagonal directions.
  • Collectible Tiny Planet iconTiny Planet: The bombs fly uncontrollably around the player, making self-damage very likely.
  • (except in Rebirth)Collectible Tractor Beam iconTractor Beam: After firing a bomb and moving, the bomb will have a homing-style effect towards the beam, but will not stay directly on the beam. Not recommended, as changing directions while firing will cause the bomb to reel back to Isaac at high speed, making self-damage very likely.

In-game Footage[ | ]

Trivia[ | ]

  • The Dr. Fetus and Collectible Epic Fetus iconEpic Fetus items are based on Dr. Fetus, the main villain in Super Meat Boy, which is a game by Edmund McMillen (the creator of The Binding of Isaac: Rebirth).
    • This is also the reason why taking the item replaces tears with bombs (Dr. Fetus fires rockets in chapter 6's bossfight in Super Meat Boy), and gives Isaac a top hat and a monocle (Dr. Fetus has a top hat and a monocle in Super Meat Boy).
  • This item is used in Demo Man (challenge #9).
  • In the original The Binding of Isaac, Dr. Fetus was unlocked by beating Boss Mom's Heart ingameMom's Heart five times instead of nine.

Gallery[ | ]

Bugs[ | ]

Bug Bug! (in Afterbirth) The black ring generated from the synergy of Dr. Fetus and Collectible Tech X iconTech X behaves as a Collectible Maw of the Void iconMaw of the Void ring and may cause Black Hearts to drop.
Bug Bug! Even though having spectral tears will make bombs not collide with obstacles, if Isaac shoots a bomb while on top of an obstacle, the bomb will collide with it, making it possible to take damage.


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