Binding of Isaac: Rebirth Wiki

Added in Afterbirth

Serpent's Kiss is an unlockable passive item added in The Binding of Isaac: Afterbirth.


  • Grants a 15% chance to fire poison tears, each tick dealing damage equal to Isaac's.
    • Poison from the shots will tick 2 times.
  • Inflicts poison on enemies who make contact with Isaac.
    • Contact poison will tick 6 times.
  • Enemies who are killed after they have been inflicted with this type of poison have a 20% chance to drop black hearts.
    • Added in Repentance This only applies to enemies that were inflicted with contact poison.
    • Enemies still can drop black hearts if the poison has worn off.


  • Not affected by luck.
  • Enemies and bosses with multiple segments, such as Chub and Larry Jr., have a chance to drop multiple Black Hearts.
  • The enemy does not need to be killed by the poison or still be poisoned when killed for the Black Hearts to drop.
  • Removed in Afterbirth † Although Stonies and Shopkeepers can't be visibly poisoned, they still can drop Black Hearts if destroyed after being touched.
  • If a boss would have been poisoned, but negates it with status immunity, they can still drop a black heart.


  • Removed in RepentanceDr. Fetus Dr. Fetus / Epic Fetus Epic Fetus: Bombs and missiles may become poisonous, and enemies hit by them may drop black hearts.
  • Removed in RepentanceMom's Knife Mom's Knife: Enemies poisoned by the knife may drop black hearts.
  • Added in RepentanceMars Mars: Dashing into enemies will often both kill enemies, and cause them to drop black hearts.
  • Tainted Forgotten Tainted Forgotten: Especially strong as you are likely to apply contact poison when attacking enemies, giving you black hearts frequently.


  • Godhead Godhead: The Godhead aura cannot inflict poison but the tears themselves may poison enemies on contact.
  • Removed in Repentance The following interactions are trivial in Repentance:

In-game Footage[]


  • Serpent's Kiss is most likely referencing Viper (Madame Hydra) from Marvel Comics, who has green lipstick and has transmitted poison through hollow fangs or poisoned lipstick before.


PC NFMD MEVX (Treasure Room adjacent to spawn)

PC E14Y Q0Z7 (Treasure Room adjacent to spawn)

PC QZC2 FNKQ (Treasure Room adjacent to spawn)

PC 7BXL YJFT (Treasure Room two down from spawn then one to the left)

PC Added in Afterbirth † Normal and hard modes only R77P MR8A (Treasure Room adjacent to spawn)