Spider Mod

Effects

Spawns a grey spider familiar that wanders around and allows Isaac to see tear damage and the health bars of all enemies.
- The spider will inflict a random status effect on any enemies it comes into contact with.
- The spider will sometimes drop a Lil' Battery or spawn a Blue Spider when a room is completed.
(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.
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!: 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: Makes Spider Mod bigger. Whether or not this impacts spawn chances or damage is unknown.