The Binding of Isaac: Antibirth Wiki
The Binding of Isaac: Antibirth Wiki
The Intruder
The Intruder Icon.png
Character Appearance
The Intruder App.png
Tear Appearance
The Intruder Tears.png
Item Type
Passive Collectible
Item ID
Pickup Quote
Invasive friend
Item Pool
Treasure Room

The Intruder is a passive item.


  • A familiar burrows in Isaac's head, firing four slowing tears in addition to Isaac's normal tears.
    • 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.
    • It will leap at enemies to deal contact damage as a Trite does, and frequently fires four slowing tears towards nearby enemies.
    • The familiar only lasts for the current room, and Isaac's head is reattached upon entering a new room.
  • Once picked up, The Intruder cannot be rerolled by any means, similar to Key Piece 1, Key Piece 2, or any of the Knife Pieces.


  • The Intruder is treated as a familiar even while in Isaac's head, and benefits from familiar synergies.


  • Brimstone: If Isaac's head pops off, it will be impossible to determine if Brimstone has been fully charged or not.
  • Transcendence: If Isaac's head pops off, Isaac will be invisible for the rest of the room aside from a shadow and orbitals.
  • Song of the Siren (trinket): Will roughly double the fire rate of the spider's tears, even while it resides inside Isaac's head.


  • The appearance of this item on Isaac is possibly a reference to the Hellbenders pilot (Zachnaphobia), in which the character "Zach" is controlled by a parasitic spider.

In-game Footage[]


VLQZ E94W (First floor treasure room)