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

Effects[]

  • Tears are replaced with bombs that explode approximately one second after being fired.
    • Removed in Afterbirth Each bomb deals 3 times the character's normal tear damage.
    • Added in Afterbirth / Removed in Repentance 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.
    • Added 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: Removed in Repentance Tear Delay × 2.5 / Added in RepentanceFire Rate ÷ 2.5.
    • 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.
    • Added in Repentance Bombs grow larger or smaller with tear size modifiers and deal no knockback to each other.

Notes[]

  • Removed 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 (but not all) bomb-enhancing effects like Mr. Mega Mr. Mega.
    • Added in Afterbirth 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[]

  • Added in Afterbirth †Apple! Apple! / Added in Afterbirth †Euthanasia Euthanasia: Damage multiplier may be applied to the non-flat damage without a visual difference. Euthanasia bombs do not retain the instant kill ability.
  • Bobby-Bomb Bobby-Bomb: Bombs home in on enemies.
  • Added in AfterbirthBomber Boy Bomber Boy: Bombs explode in a large cross-shaped pattern.
  • Added in RepentanceBlood Bombs Blood Bombs: Bombs leave behind a pool of red creep.
  • Added in RepentanceBrimstone Bombs Brimstone Bombs: The activation rate of the Brimstone Brimstone 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.
  • Butt Bombs Butt Bombs: All bombs inherit the Butt Bomb effects.
    • Added 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.
    • Unlike normal Butt Bombs, this synergy cannot heal Added in Afterbirth Brownie Brownie, Added in Repentance Clog Clog, Added in Repentance Colostomia Colostomia, Added in Afterbirth Dangle Dangle, or Dingle Dingle. Both the explosion and the cloud effect deal full damage.
  • Added in AfterbirthCricket's Body Cricket's Body: The bombs split outwards into 4 tiny bombs, which detonate almost immediately.
    • Added in Repentance The split bombs deal a flat 35 damage.
  • Added in RepentanceC Section C 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: Additional copy of this item, such as from Added in AfterbirthDiplopia Diplopia / Added in Afterbirth †Crooked Penny Crooked Penny, grants a multi-shot effect without tears down.
  • Added in AfterbirthExplosivo Explosivo: The bombs have a chance of sticking to an enemy. These bombs have the same appearance as Added in AfterbirthSticky Bombs Sticky Bombs, but do not spawn spiders.
  • Added in RepentanceEye Sore Eye Sore: When Isaac shoots, he has a chance to fire 1-3 additional bombs in random directions.
  • Fire Mind Fire Mind / Added in AfterbirthHot Bombs Hot Bombs: The bombs leave behind a fire that damages enemies on contact after exploding, and bombs themselves deal Added in Afterbirth / Removed in Repentance 1 point of damage/Added in Repentance 16 damage on contact.
  • Added in RepentanceGhost Bombs Ghost Bombs: 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.
  • Godhead Godhead: Does not give bombs the damaging aura, but does give them the homing effect.
  • Added in Afterbirth †Haemolacria Haemolacria: 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 + Sad Bombs Sad Bombs: Sad bombs from Haemolacria tears shoot 10 Haemolacria tears, which then scatters into bombs without Sad Bombs' property.
  • Ipecac Ipecac: The bombs become Bob's Curse Bob's Curse bombs. Isaac is immune to his bomb shots (not explosives or placed bombs) and the damage is massively increased, as the +40 damage from Ipecac is run through the damage multiplier of Dr. Fetus. Shots will also explode immediately on impact with enemies, rocks, poops, angel statues, devil statues, or walls.
    • Added in Repentance The effect on damage becomes a flat +2 bonus instead of +40. Does not apply Ipecac's tears down. Bombs leave behind a cloud of poison gas that will poison enemies in contact with it aside from the main target.
    • Ipecac + Cricket's Body Cricket's Body / The Parasite The Parasite / Polyphemus Polyphemus / Sad Bombs Sad Bombs / Added in AfterbirthScatter Bombs Scatter Bombs: Isaac is immune to the main bomb shot, but not to the explosive shrapnel.
      • Added in Repentance Isaac is immune to the shrapnel bombs left by Cricket's Body, The Parasite, Polyphemus, and Scatter Bombs.
    • Ipecac + Added in AfterbirthTech X Tech X: Isaac is immune to the main bomb shot, but not the explosions created by the laser ring.
  • The Ludovico Technique The Ludovico Technique: The bomb can be controlled before exploding, similar to Epic Fetus Epic Fetus. Isaac does not shoot bombs while controlling it.
  • Added in AfterbirthMonstro's Lung Monstro's Lung: Monstro's Lung has priority. Does not apply Dr. Fetus' tears down. Fires 6 bombs which detonate simultaneously.
    • Multi-shot effects add 1 bomb to the barrage, up to 21 bombs.
  • Mr. Mega Mr. Mega: Adds 25 flat damage to bomb explosions.
  • Added in AfterbirthMysterious Liquid Mysterious Liquid: Exploding bombs leave behind a large pool of creep.
  • Added in AfterbirthThe Parasite The Parasite: Upon exploding, bombs split into two other bombs, which explode almost immediately.
    • The split bombs deal a flat Added in Afterbirth / Removed in Repentance 24 damage/Added in Repentance 40 damage.
  • Added in Repentance Piercing tears: Bombs deal 2.5x Isaac's damage to enemies when passing through them.
  • Poison tears: This is guaranteed by Bob's Curse Bob's Curse, Ipecac Ipecac, and Scorpio Scorpio, and also has a chance to trigger from The Common Cold The Common Cold, Pinky Eye Pinky Eye or Added in AfterbirthSerpent's Kiss Serpent's Kiss.
    • Removed in Repentance Poison effects will give bombs a flat +50 damage.
    • Added in Repentance Poison bombs leave behind a cloud of toxic gas that will poison enemies in contact with it aside from the main target.
  • Polyphemus Polyphemus: The bombs increase in size and do increased damage.
    • Added in Afterbirth The bombs become Mr. Mega Mr. Mega bombs. After they detonate, they leave behind a regular-sized bomb that deals a flat Added in Afterbirth / Removed in Repentance60 damage/Added in Repentance100 damage, much like a standard bomb.
  • Proptosis Proptosis: Distance penalty does not apply.
    • Added in Repentance Damage for Dr. Fetus' damage calculation is tripled.
  • Remote Detonator Remote 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.
  • Added in RepentanceRocket in a Jar Rocket 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.
  • Added in AfterbirthSad Bombs Sad Bombs: Fires tears as normally placed Sad Bombs would.
    • Added 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.
  • Added in AfterbirthScatter Bombs Scatter Bombs: The bombs split into Added in Afterbirth / Removed in Repentance 2-4/Added in Repentance 4-5 tiny bombs. The bombs deal half damage of the bomb it came from.
    • Added 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.
  • Added in AfterbirthTech X Tech X: Dr. Fetus has priority. The bombs have a laser ring around them.
  • Tough Love Tough Love: Damage multiplier may be applied to the non-flat damage without a visual difference.
    • Added in Afterbirth / Removed in Afterbirth † Tears that would have fired a tooth shot instead become a Mr. Mega Mr. Mega bomb, adding a flat 25 damage and shaking the screen.
    • Added in Repentance Damage multiplier may be applied to the non-flat damage without a visual difference.
  • Added in RepentanceUranus Uranus: The bombs freeze enemies upon killing them.

Interactions[]

  • Anti-Gravity Anti-Gravity: Overridden by Dr. Fetus. Tear delay decrease is still applied.
  • Added in RepentanceBrain Worm Brain Worm: No effect on bombs.
  • Brimstone Brimstone: Overridden by Dr. Fetus. The beams can still appear from other sources such as Sad Bombs Sad Bombs.
    • Added in Afterbirth / Removed in Repentance Isaac continuously fires bombs while charging the beam. Overrides Azazel Azazel's Brimstone.
  • Removed in RepentanceChocolate Milk Chocolate Milk: The bombs can't be charged, but reduces Isaac's tear delay by 20%.
  • Removed in RepentanceCricket's Body Cricket's Body: The bombs do not split. Range is greatly decreased.
  • Added in Afterbirth †Compound Fracture Compound Fracture: Bombs do not split. Stat changes still apply.
  • Cursed Eye Cursed Eye: Overridden by Dr. Fetus.
  • Epic Fetus Epic Fetus: Overrides Dr. Fetus.
  • The Forgotten The 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.
  • Added in AfterbirthTear Detonator Tear Detonator: No effect on bombs.
  • Removed in Repentance Guppy Guppy: Explosions do not spawn flies.
  • Added in RepentanceImmaculate Heart Immaculate Heart: Orbital tears do not become bombs.
  • Added in Repentance Kidney Stone Kidney Stone / Number One Number One / Pluto Pluto: The bombs lose almost all of their range, and cannot be improved by range ups, shot speed or any other method.
  • Removed in RepentanceKidney Stone Kidney Stone: The range decrease applies, but since the tear height 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.
  • Added in Afterbirth †Lachryphagy Lachryphagy: Dr. Fetus bombs are not affected. Lachryphagy tears can still appear from other sources such as Sad Bombs Sad Bombs.
  • Removed in RepentanceLead Pencil Lead Pencil: Overridden by Dr. Fetus.
    • Added in Repentance 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.
  • A Lump of Coal A Lump of Coal: No damage increase.
  • Added in AfterbirthMarked Marked: Overridden by Dr. Fetus. Tear delay decrease is still applied.
    • Added in Repentance Creates a target reticle at which the bombs continuously fire.
  • Removed in AfterbirthMonstro's Lung Monstro's Lung: Same effect as 20/20 20/20, except retains fire rate.
    • Monstro's Lung + Ipecac Ipecac: 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.
  • Mom's Eye Mom's Eye: Grants a chance to shoot an extra bomb from the back of Isaac's head.
    • Mom's Eye + Added in RepentanceEye of the Occult Eye 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.
  • Mom's Knife Mom's Knife:
    • Removed in Afterbirth / Re-added in Repentance Overrides Dr. Fetus. Knives can still appear from other sources such as Sad Bombs Sad Bombs.
    • Added in Afterbirth / Removed in Repentance Isaac continuously fires bombs while charging the knife.
    • Mom's Knife + Added in AfterbirthIncubus Incubus: The Incubus loses the ability to fire out bombs.
  • Added in RepentanceMucormycosis Mucormycosis: No effect on the bombs.
  • My Reflection My Reflection: The bombs lose momentum and slide back towards Isaac, making self-damage very likely.
  • Added in RepentanceNeptunus Neptunus: Overridden by Dr. Fetus.
  • Added in RepentanceOcular Rift Ocular Rift: No effect.
  • Added in Afterbirth †Ouroboros Worm Ouroboros Worm: Does not affect the trajectory of the bombs. Turns some bombs into homing bombs, similar to Bobby-Bomb Bobby-Bomb.
  • Removed in AfterbirthThe Parasite The Parasite: No effect.
  • Removed in Repentance Piercing tears: The bombs pierce through enemies, which makes killing them more difficult.
  • Added in Afterbirth †Pop! Pop!: The bombs are not affected. Pop! tears can still appear from other sources such as Sad Bombs Sad Bombs.
  • Added in Afterbirth †Sinus Infection Sinus Infection: No effect on the bombs.
  • Soy Milk Soy Milk: Shoots rapid-fire mini bombs. Can create a line of bombs which can be difficult to avoid taking damage from. The explosions from bombs do not repel the other bombs, though.
    • Soy Milk + Added in AfterbirthThe Parasite The Parasite: The split bombs will repel the mini-bombs, making it very difficult to avoid taking damage.
  • 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.
  • Added in RepentanceSpirit Sword Spirit Sword: Overrides Dr. Fetus.
    • Spirit Sword + Added in Afterbirth †Haemolacria Haemolacria: The split bombs can appear from Spirit Sword's projectiles.
  • Added in AfterbirthSticky Bombs Sticky Bombs: The bombs stick to enemies, but enemies killed by the bomb will not spawn Blue Spiders.
  • Technology Technology:
    • Removed in Afterbirth / Re-added in Repentance Overridden by Dr. Fetus. Lasers can still appear from other sources such as Sad Bombs Sad Bombs.
    • Added in Afterbirth / Removed in Repentance Both fire normally.
  • Added in Afterbirth †Technology Zero Technology Zero: Dr. Fetus bombs do not generate electricity. Tears from other sources such as Sad Bombs Sad Bombs can still generate electricity.
  • Added in RepentanceTechnology 2 Technology 2: The bombs are seemingly pushed forward by the laser, giving the appearance of much longer range.
  • Tiny Planet Tiny Planet: The bombs fly uncontrollably around the player, making self-damage very likely.
  • Added in AfterbirthTractor Beam Tractor 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.
  • Added in Afterbirth †Trisagion Trisagion: Overridden by Dr. Fetus. Trisagion blasts can still appear from other sources such as Sad Bombs Sad Bombs.

In-game Footage[]

Gallery[]

Trivia[]

  • The Dr. Fetus and Epic 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 item is used in Demo Man (challenge #9).
  • In the original The Binding of Isaac, Dr. Fetus was unlocked by beating Mom's Heart five times instead of nine.

Seeds[]

PC Normal and hard modes only KP6M WZAJ (Treasure Room adjacent to spawn)

PC Normal mode only 9LCJ RQG8 (Treasure Room adjacent to spawn)

PC Added in Afterbirth † RX1E JBV9 (First floor Treasure Room)

PC Added in Repentance CXZG 2YD6 (Treasure room →↓ from spawn)

PC Added in Repentance DBEX HEBR (Tresure room adjacent to spawn)

PS4 Added in Afterbirth † Normal mode only BGGY NWTC (First Treasure Room)

PS4 Added in Afterbirth † Normal mode only LYCL LAAP (Treasure Room adjacent to spawn)

Bugs[]

Bug Bug! Added in Afterbirth / Removed in Afterbirth † The black ring generated from the synergy of Dr. Fetus and Tech X Tech X behaves as a Maw of the Void Maw 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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