The Intruder is a passive item.
- Isaac fires four slowing tears in addition to 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.
- 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.
- 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.
VLQZ E94W (First floor treasure room)