| 4 rooms|
|(page 5, column 2, line 3)
| Open 20 locked chests|
Mr. ME! is an unlockable activated item added in Booster Pack #3.
- Summons a ghost near Isaac that will follow him around, and summons a controllable blue crosshair. After a few seconds, the crosshair disappears, and the ghost will perform an action depending on what the crosshair was targeting:
- Items, pickups, trinkets, brown/red/spiked chests: Brings it to Isaac. Works in shops and devil deals as well, making them effectively free. Stealing an item has a chance to fail. If that happens a buzzer sound will play out and the ghost will disappear without doing anything.
- Golden/eternal/stone chests: Opens the chest for free.
- Buttons: Presses the button.
- Enemies: Attacks the enemy until either the ghost or the enemy dies.
- Doors: Opens the door, even if it is locked. Functions the same as Dad's Key when being used in this way. This includes the door to Mega Satan.
- Secret room entrances: Explodes, opening the entrance.
- Destructible obstacles, shopkeepers, machines, and beggars: Explodes and destroys them.
- When stealing an item, the player should aim between the item and the price; otherwise, it has a chance to fail.
- Stealing an item from a shop will restock it with another item. This happens even if Isaac does not have Restock.
- If the crosshair is not targeting anything when the crosshair disappears, the ghost will interact with the object closest to the crosshair.
- If the room has nothing to interact with, the ghost will disappear without doing anything.
- The ghost cannot pick up sticky nickels, and will disappear upon touching them.
- The ghost can press the button in Greed Mode, allowing waves to be stopped without taking damage.
- In rooms with multiple pedestal items where only one can be taken, if the ghost is carrying a pedestal while Isaac picks up a different pedestal item, the ghost will disappear. This prevents taking both items for free.
- When used against Isaac (Boss) or ??? (Boss), the ghost will still try to chase the boss even when he flies away.
The game crashes if Mr. ME! is used on the trophy at the end of a challenge.
Using Mr. ME! together with Car Battery to pick up items will cause Isaac to pass through the item as if it was not there. You can still pick it up by exiting the room and entering again, which fixes the pedestal, but this causes trouble with Angel Rooms and Devil Rooms as the entrance disappears when you exit.
If the Devil Room or Angel Room disappears after leaving it, using Mr. ME! will still attempt to unlock the doorway back to it. This allows you to move through the wall as if there were a door there, but you will not be able to enter the Devil Room or Angel Room.
- Mr. ME! is based on this Steam Workshop item by Jean-Alphonse, originally known as Mr. Meeseeks.
- Mr. ME! is a reference to Mr. Meeseeks from Rick and Morty, which spawn from a box and stop existing after completing their given task.
- The pickup quote also refers to a catchphrase used by Mr. Meeseeks.
The ghost summoned by Mr. ME!