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 Mega Satan's health bar and is the only way to see his health.
  • Spider Mod shows the health of invincible enemies, holes created by Little Horn Little Horn, and the golden statue of Ultra Greed Ultra Greed.
  • Spider Mod doesn't show if a segmented enemy has individual segment health like Larry Jr. Larry Jr. or a health pool like Chub Chub. Against enemies with invulnerable segments such as Carrion Queen Carrion Queen and Scolex 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 Added in Afterbirth † Mushroom Mushrooms, Stone Grimace Stone Grimaces, and similar enemies will be inaccurate.
  • Added in Afterbirth † If Isaac transforms into Spider Baby 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.

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  • 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.