AIsaac The Forbidden is an unlockable familiar in The Bimbing of AIsaac: Reedged, a mod for The Binding of Isaac.

In rooms with non-boss enemies, possesses one of them.

The possessed enemy is 33.3% faster, but also deals contact and projectile damage to other enemies.

When the enemy dies, it chooses a new target.

In unexplored rooms, he might possess one of the things he is interested in:

Fire Place → extinguishes it.
Shopkeeper → destroys it.
I AM ERROR Shopkeeper → crashes the game.
Megatroll Bomb → turns it into lit Giga Bomb.
Heart/ Heart (half) → Scared Heart.
Heart (double) → Scared Heart×2.
Any Card/Rune → Glitched Card.
Any Pill → Glitched Pill.
Chest/ Mimic Chest/ Spiked Chest → Red Chest or Haunted Chest.

If there is nothing he is interested in, possesses Isaac (no effect).
Can't possess Isaac if he is in a ghost form / it is a ghost character.

Get all completion marks as AIsaac on Hard difficulty.

AIsaac The Forbidden can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for AIsaac The Forbidden have been documented.

* Note that not all possible synergies and interactions are listed here.

AIsaac the Forbidden is based on AIsaac 10 who's been known as the most cursed AIsaac that broke Kamijoan's streams on several occasions and possessed other AIsaacs. He is the most powerful and mysterious AIsaac so far.

• Download The Bimbing of AIsaac: Reedged from the Steam Workshop.