Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Added in Afterbirth

Spider Mod is a passive item added in the Binding of Isaac: Afterbirth expansion.


  • Spawns a grey spider familiar that wanders around and allows Isaac to see tear damage and the health bars of all enemies.
  • Added in Afterbirth † This item belongs to the Spider Baby set. Collecting three items from this set will transform Isaac into a humanoid spider.


  • Removed in Repentance For the sake of simplicity, all damage values shown are multiplied by 10 and rounded up to the nearest number.
    • Added in Repentance Damage values are no longer multiplied or rounded.
  • All stats effect damage dealt by Spider Mod is based on Isaac's damage stat.
  • Spider Mod reveals Mega Satan's health bar and is the only way to see his health.
    • Added in Repentance In Repentance, doesn't reveal Mega Satan's life bar during his second phase anymore.
    • Added in Repentance Spider Mod also reveals the health bar for Mother, the Ultra Harbingers, and The Beast. (Note: The Health Bar for The Beast might be in the lava, making Spider Mod's health reveal effect for that portion of the fight useless.)(Needs Confirmation)
  • Spider Mod shows the health of invincible enemies, holes created by Little Horn, and the golden statue of Ultra Greed.
  • Spider Mod doesn't show if a segmented enemy has individual segment health like Larry Jr. or a health pool like Chub. Against enemies with invulnerable segments such as Carrion Queen and Scolex, its indicators will not differentiate between damage dealt to invulnerable and vulnerable segments.
  • Spider Mod's damage doesn't account for enemy damage reduction or invulnerability, which means that the damage indicators for Mushrooms, Stone Grimaces, and similar enemies will be inaccurate.
  • Added in Afterbirth † If Isaac transforms into Spider Baby, it spawns a spider familiar who works similarly to Spider Mod.


  • BFFS! BFFS!: Makes Spider Mod bigger and increases the chance for Spider Mod to spawn a battery or blue spider. No effect on stat effect damage.
  • Hive Mind Hive Mind: Makes Spider Mod bigger. Whether or not this impacts spawn chances or damage is unknown.

In-game Footage[]


  • This item is a reference to Spidermod, a modification to the original Binding of Isaac, which was made by one of the lead Rebirth developers, Spider853. One feature of Spidermod was to show damage numbers onscreen.