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: Delay * 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.
- Bombs grow larger or smaller with tear size modifiers and deal no knockback to each other.
- Angelic Prism Split bombs still deal knockback to eachother.
- Dr. Fetus is a special item.
- 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 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 now 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: Bombs split outwards into 4 tiny bombs, which detonate almost immediately.
- Explosivo: 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: Bombs leave behind a fire that damages enemies on contact after exploding, and bombs themselves deal 1 point of 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: Significantly increased tear delay. Isaac fires a large arcing tear reminiscent of a bomb that scatters into 3-5 bombs that explode simultaneously. Scattered bombs deal knockback to each other.
- Ipecac: 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 now becomes a flat +2 bonus instead of +40. Bombs leave behind a cloud of poison gas that will poison enemies in contact with it aside from the main target. Isaac remains immune to the bomb shot.
- Ipecac + Cricket's Body/ Polyphemus/ Sad Bombs/ Scatter Bombs: Isaac is immune to the main bomb shot, but not to the explosive shrapnel.
- Isaac is now immune to the shrapnel bombs left by Cricket's Body, 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: Bomb can be controlled before exploding, similar to Epic Fetus. Isaac does not shoot bombs while controlling it.
- Monstro's Lung: Shoots 6 bombs that need to be fully charged before firing. The bombs detonate simultaneously.
- 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 and deal a flat 24 damage.
- : The split bombs now deal a flat 40 damage.
- Poison tears: Poison effects will give bombs a flat +50 damage. This is guaranteed by Bob's Curse, Ipecac, and Scorpio, and also has a chance to trigger from The Common Cold or Pinky Eye.
- No damage increase from poison. Poison bombs have a chance to trigger from Serpent's Kiss.
- Poison bombs leave behind a cloud of toxic gas that will poison enemies in contact with it aside from the main target.
- Polyphemus: Bombs increase in size and do increased damage.
- 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: Increases damage with no distance penalty.
- Remote Detonator: 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 as normal tears.
- Sad Bombs: Fires tears as normally placed Sad Bombs would.
- The activation rate is now 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.
- Tech X: 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: 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.
- : Isaac continuously fires bombs while charging the blood laser. Overrides Azazel's blood laser.
- Chocolate Milk: Bombs can't be charged, but reduces Isaac's tear delay by 20%.
- Cricket's Body: 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.
- 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: Not recommended. 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: Overridden by Dr. Fetus.
- Lead Pencil: Overridden by Dr. Fetus.
- Not recommended. Every fifteenth shot will cause a barrage of short range shockwaves, which will inevitable hurt Isaac.
- 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.
- Mom's Eye: Grants a chance to shoot an extra bomb from the back of Isaac's head.
- Mom's Knife: Overrides Dr. Fetus.
- My Reflection: Not recommended, as 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 / Spectral tears: Using piercing/spectral tears is not recommended, as it will make aiming at and killing enemies or destroying obstacles more difficult.
- Pop!: Overridden by Dr. Fetus.
- 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: Not recommended. Side bombs will repel the mini-bombs, making it very difficult to avoid taking damage.
- Sticky Bombs: Bombs stick to enemies, but enemies killed by the bomb will not spawn Blue Spiders.
- Technology: Overridden by Dr. Fetus.
- Both fire normally.
- Technology Zero: Overridden by Dr. Fetus.
- Technology 2: The bombs are seemingly pushed forward by the laser, giving the appearance of much longer range.
- Tiny Planet: Not recommended. 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.
- 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)
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!||PC The 4 rockets generated from the synergy of Dr. Fetus, Rocket in a Jar and Angelic Prism tend to the right, no matter the starting firing direction.|
|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|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|