Dr. Fetus is an unlockable passive item.
- Tears are replaced with Bombs that explode approximately one second after being fired.
- Each bomb deals 3 times the character's normal tear damage.
- 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.
- 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: Tear Delay × 2.5 / Fire 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.
- 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 range stat effectively not working for Dr. Fetus with exceptions being Number One and Kidney Stone both of which make velocity absurdly low.
- Bombs grow larger or smaller with tear size modifiers and deal no knockback to each other.
- 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.
- 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.
- Apple! / 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: Bombs home in on enemies.
- Homing Tears: Bombs home in on enemies.
- Bomber Boy: Bombs explode in a large cross-shaped pattern.
- Blood Bombs: Bombs leave behind a pool of red creep.
- Brimstone Bombs: The activation rate of the 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: All bombs inherit the Butt Bomb effects.
- 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 Brownie, Clog, Colostomia, Dangle, or Dingle. Both the explosion and the cloud effect deal full damage.
- Cricket's Body: The bombs split outwards into 4 tiny bombs, which detonate almost immediately.
- The split bombs deal a flat 35 damage.
- 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.
- The fetuses' bombs do not benefit from Isaac's bomb effects such as Hot Bombs or Bobby-Bomb. However, they do benefit from Isaac's tear effects and have appearance of the corresponding bombs. For example, Hot Bombs from Fire Mind, Bobby-Bomb from Homing Tears. As such, Cricket's Body, The Parasite and Polyphemus leave a subsequent bomb or bombs, and Mysterious Liquid leaves a creep.
- C Section + Ipecac: The fetuses explode before dropping any bomb.
- Dr. Fetus: Additional copy of this item, such as from Diplopia / Crooked Penny, grants a multi-shot effect without tears down.
- Explosivo: The bombs have a chance of sticking to an enemy. These bombs have the same appearance as Sticky Bombs, but do not spawn spiders.
- Eye Sore: When Isaac shoots, he has a chance to fire 1-3 additional bombs in random directions.
- Fire Mind / Hot Bombs: The bombs leave behind a fire that damages enemies on contact after exploding, and bombs themselves deal 1 point of damage/ 16 damage on contact.
- 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: Does not give bombs the damaging aura, but does give them the homing effect.
- 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 from Haemolacria tears shoot 10 Haemolacria tears, which then scatters into bombs without Sad Bombs' property.
- Ipecac: The bombs become 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.
- 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 / The Parasite / Polyphemus / Sad Bombs / Scatter Bombs: Isaac is immune to the main bomb shot, but not to the explosive shrapnel.
- Isaac is immune to the shrapnel bombs left by Cricket's Body, The Parasite, Polyphemus, and Scatter Bombs.
- Ipecac + Tech X: Isaac is immune to the main bomb shot, but not the explosions created by the laser ring.
- The Ludovico Technique: The bomb can be controlled before exploding, similar to Epic Fetus. Isaac does not shoot bombs while controlling it.
- 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: Adds 25 flat damage to bomb explosions.
- Mysterious Liquid: Exploding bombs leave behind a large pool of creep.
- The Parasite: Upon exploding, bombs split into two other bombs, which explode almost immediately.
- The split bombs deal a flat 24 damage/ 40 damage.
- Piercing tears: Bombs deal 2.5x Isaac's damage to enemies when passing through them.
- Poison tears: This is guaranteed by Bob's Curse, Ipecac, and Scorpio, and also has a chance to trigger from The Common Cold, Pinky Eye or Serpent's Kiss.
- Poison effects will give bombs a flat +50 damage.
- Poison bombs leave behind a cloud of toxic gas that will poison enemies in contact with it aside from the main target.
- Polyphemus: The bombs increase in size and do increased damage.
- The bombs become Mr. Mega bombs. After they detonate, they leave behind a regular-sized bomb that deals a flat 60 damage/100 damage, much like a standard bomb.
- Proptosis: Distance penalty does not apply.
- Damage for Dr. Fetus' damage calculation is tripled.
- 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.
- 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.
- Sad Bombs: Fires tears as normally placed Sad Bombs would.
- 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.
- Scatter Bombs: The bombs split into 2-4/ 4-5 tiny bombs. The bombs deal half damage of the bomb it came from.
- 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.
- Tech X: Dr. Fetus has priority. The bombs have a laser ring around them.
- Tough Love: Damage multiplier may be applied to the non-flat damage without a visual difference.
- Tears that would have fired a tooth shot instead become a Mr. Mega bomb, adding a flat 25 damage and shaking the screen.
- Damage multiplier may be applied to the non-flat damage without a visual difference.
- Uranus: The bombs freeze enemies upon killing them.
- Anti-Gravity: Overridden by Dr. Fetus. Tear delay decrease is still applied.
- Brain Worm: No effect on bombs.
- Brimstone: Overridden by Dr. Fetus. The beams can still appear from other sources such as Sad Bombs.
- Isaac continuously fires bombs while charging the beam. Overrides Azazel's Brimstone.
- Chocolate Milk: The bombs can't be charged, but reduces Isaac's tear delay by 20%.
- Cricket's Body: The bombs do not split. Range is greatly decreased.
- Compound Fracture: Bombs do not split. Stat changes still apply.
- Cursed Eye: Overridden by Dr. Fetus.
- Epic Fetus: Overrides Dr. Fetus.
- 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.
- Tear Detonator: No effect on bombs.
- Guppy: Explosions do not spawn flies.
- Immaculate Heart: Orbital tears do not become bombs.
- Kidney Stone / Number One / Pluto: The bombs lose almost all of their range, and cannot be improved by range ups, shot speed or any other method.
- 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.
- Lachryphagy: Dr. Fetus bombs are not affected. Lachryphagy tears can still appear from other sources such as Sad Bombs.
- Lead Pencil: Overridden by Dr. Fetus.
- 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: No damage increase.
- Marked: Overridden by Dr. Fetus. Tear delay decrease is still applied.
- Creates a target reticle at which the bombs continuously fire.
- Monstro's Lung: Same effect as 20/20, except retains fire rate.
- Monstro's Lung + 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: Grants a chance to shoot an extra bomb from the back of Isaac's head.
- Mom's Eye + 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:
- Mucormycosis: No effect on the bombs.
- My Reflection: The bombs lose momentum and slide back towards Isaac, making self-damage very likely.
- Neptunus: Overridden by Dr. Fetus.
- Ocular Rift: No effect.
- Ouroboros Worm: Does not affect the trajectory of the bombs. Turns some bombs into homing bombs, similar to Bobby-Bomb.
- The Parasite: No effect.
- Piercing tears: The bombs pierce through enemies, which makes killing them more difficult.
- Pop!: The bombs are not affected. Pop! tears can still appear from other sources such as Sad Bombs.
- Sinus Infection: No effect on the bombs.
- 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 + 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.
- Spirit Sword: Overrides Dr. Fetus.
- Spirit Sword + Haemolacria: The split bombs can appear from Spirit Sword's projectiles.
- Sticky Bombs: The bombs stick to enemies, but enemies killed by the bomb will not spawn Blue Spiders.
- Overridden by Dr. Fetus. Lasers can still appear from other sources such as Sad Bombs.
- Both fire normally.
- Technology Zero: Dr. Fetus bombs do not generate electricity. Tears from other sources such as Sad Bombs can still generate electricity.
- Technology 2: The bombs are seemingly pushed forward by the laser, giving the appearance of much longer range.
- Tiny Planet: The bombs fly uncontrollably around the player, making self-damage very likely.
- 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.
- Trisagion: Overridden by Dr. Fetus. Trisagion blasts can still appear from other sources such as Sad Bombs.
- 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.
PC 9LCJ RQG8 (Treasure Room adjacent to spawn)
PC RX1E JBV9 (First floor Treasure Room)
PC CXZG 2YD6 (Treasure room →↓ from spawn)
PC DBEX HEBR (Tresure room adjacent to spawn)
PC 80HT K4SQ (Tresure room adjacent to spawn)
PS4 BGGY NWTC (First Treasure Room)
PS4 LYCL LAAP (Treasure Room adjacent to spawn)
|Bug!||The black ring generated from the synergy of Dr. Fetus and Tech X behaves as a Maw of the Void ring and may cause Black Hearts to drop.|
|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.|
|Mom's Heart Unlocks|
|The Binding of Isaac: Rebirth|
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