The Intruder

The Intruder is a passive item added in The Binding of Isaac: Repentance.

Effects

 * Gives Isaac a spider familiar that burrows in Isaac's head, firing four slowing tears in addition to Isaac's normal tears.
 * The slowing tears deal 1.5 damage each, and are fired at a rate of once every 1.5 seconds.
 * These tears are unaffected by Isaac's damage and tears stats; they have fixed damage and fire rate.
 * Upon taking damage, there is a chance that Isaac's head will pop, spawning friendly spiders, and release the Intruder familiar, who will leap at enemies to deal contact damage, and fires four slowing tears towards nearby enemies instead of Isaac.
 * The spider familiar deals up to 4.5 contact damage depending on how fast it's moving and fires slowing tears twice as fast compared to when it's in Isaac's head.
 * The chance for activation goes up to 100% at 4 luck.
 * The familiar lasts for the current room, and Isaac's head is reattached upon entering a new room.

Synergies

 * Doubles the number of tears fired from Isaac's head (if both copies fire at the same time, the tears will stack perfectly so it can be difficult to tell). If The Intruder is released, then interacts normally and spawns a copy.
 * Increases The Intruder's tear and contact damage.

Interactions

 * : The Intruder can be sacrificed even while in Isaac's head.
 * : The Intruder's tears come from Lilith, despite her blindfold.

Trivia

 * The spider resembles the spider present in the pilot episode of Hellbenders, a popular flash cartoon and failed candidate for an Adult Swim show. The item itself may be a reference to this episode.