Binding of Isaac: Rebirth Wiki

The Parasite is an unlockable passive item.


  • Tears that deal more than 1.0 damage split into two tears with half damage and half remaining range on impact with obstacles or enemies.
    • Damage less than 1.0 causes the tears to simply disappear.
    • The splitting can keep up as long as the tears have range remaining and the damage of the split tears stays above 0.5.
    • Split tears are scaled down by 0.5x from the parent one, ignoring damage based size reduction.


  • Added in Afterbirth †Angelic Prism Angelic Prism: All tears split by the prism will burst into split tears when hitting obstacles.
  • Bob's Rotten Head Bob's Rotten Head: Two further explosions appear perpendicular to the head's direction of travel when it blows up.
  • Added in RepentanceC Section C Section: Fetuses fire short-ranged tears constantly while in contact with an enemy.
  • Added in Afterbirth †Compound Fracture Compound Fracture: Both tear split effects happen simultaneously.
  • Added in AfterbirthContinuum Continuum / Spectral tears: When tears pass through solid objects, like rocks, they will split, resulting in many tears shooting out from every rock the original tear passed through.
  • Cricket's Body Cricket's Body: Two groups of this item's four tears, creating eight additional miniature tears on every point of impact instead.
  • Added in Afterbirth †Flat Stone Flat Stone: Every time tears bounce, burst tears spawn.
  • Added in Afterbirth †Lachryphagy Lachryphagy: Fed tears split into 12 tears. When tears are minimally fed and hit an obstacle, they will split into 5 Lachryphagy burst tears and Parasite burst tears.
  • Added in Afterbirth †Lead Pencil Lead Pencil / Monstro's Lung Monstro's Lung: All tears in tear barrage will burst into split tears when hitting obstacles or enemies.
  • The Ludovico Technique The Ludovico Technique: Repeatedly spawns miniature tears when on top of an enemy, greatly increasing damage.
  • Piercing tears: Split tears form for each hit as the tears pass through the enemies.
  • Tiny Planet Tiny Planet: The split tears will continue to orbit Isaac, increasing damage potential.
  • Added in AfterbirthTractor Beam Tractor Beam: The split tears will be forced directly forward, impacting whatever caused the first tear to split. This increases damage immensely.
    • If all shots connect, effective damage will be multiplied by 2 + log2(damage).
  • Added in Afterbirth †Trisagion Trisagion: When beams hit obstacles, the beam will split; the split beams can split again when hitting other obstacles.


  • Aquarius Aquarius: No effect.
    • Added in Repentance Creep trail turns dark orange but doesn't affect the creep itself.
  • Removed in Repentance Brimstone Brimstone: Overrides The Parasite.
    • Added in Repentance 2 beams that deal full damage will be fired perpendicular to the main beam at the closest point of intersection with an enemy or obstacle, or at the end of the laser when playing as Azazel Azazel.
  • Added in AfterbirthDiplopia Diplopia: No effect.
  • Removed in Afterbirth Dr. Fetus Dr. Fetus: Bombs turn orange and with no other effect.
    • Added in Afterbirth Bombs split into two bombs that deal 40 damage each upon detonation.
      • Dr. Fetus + Added in RepentanceRocket in a Jar Rocket in a Jar: Rockets split into two bombs (not rockets) upon detonation.
  • Epic Fetus Epic Fetus: Overrides The Parasite.
  • Added in RepentanceEye of the Occult Eye of the Occult: Split tears can be controlled similarly to normal tears, which results in a large amount of floating tears.
  • Ipecac Ipecac: The Ipecac tear will spawn two smaller explosive tears when it collides with a solid object, but not with an enemy. These tears can spawn tears on their own as well, potentially leading to huge chain reactions. Having Added in AfterbirthHost Hat Host Hat or Pyromaniac Pyromaniac is strongly recommended.
  • Added in AfterbirthKidney Stone Kidney Stone: Drastically decreases range making it less likely for tears to split. The stone will not split.
  • Removed in Repentance Mom's Knife Mom's Knife: Knife turns orange with no other effect.
    • Added in Repentance Knife splits into two smaller, perpendicular knives that deal full damage on hitting an enemy.
  • Rubber Cement Rubber Cement: Tears only split when hitting enemies and no longer off the wall or most obstacles.
  • Soy Milk Soy Milk: Without any damage increases, Soy Milk tears deal under 1.0 damage and cannot split until the situation is rectified with other items.
  • Added in RepentanceSpirit Sword Spirit Sword: No effect on swings and spins. Projectiles bursts into 2 small tears.
  • Removed in Repentance Technology Technology: Overrides The Parasite.
    • Added in Repentance Laser splits into two perpendicular beams that deal full damage upon hitting an obstacle or enemy.
  • Added in AfterbirthTech X Tech X: Overrides The Parasite. Laser rings become orange.

In-game Footage[]


PC FR6X 2BGZ (Room adjacent to spawn)

PC Added in Afterbirth † ZF2M AQ7K (Room adjacent to spawn)

PS4 XX1T QXN1 (Room adjacent to spawn)

Vita NZ7X G61B (First floor Treasure Room)

Switch Normal mode only 7NN1 6CZS (Starting item as Eden)

Switch Greed mode only GB8R QPMY (First Golden Treasure Room)