Multidimensional Baby

Multidimensional Baby is a passive item added in the Binding of Isaac: Afterbirth expansion.

Effects[edit | edit source]

Spawns a familiar that follows Isaac's path with a 2.5-second delay.
When a friendly tear passes through Multidimensional Baby, the tear splits into two parallel tears that gain a 1.33x speed boost, +4 shot height, and also a visual black and white flashing effect.

It is possible to crash the game when combining this item with rapid-fire or multi-shot laser tears.
Duplicated tears will deal the same damage as Isaac's tears.

Brimstone: If a brimstone laser is shot through the baby, it will double the laser.
- Azazel's short-ranged Brimstone attack will also be "fired again" from the baby, increasing the range.
Cricket's Body/ The Parasite: Tears that pass through Multidimensional Baby will duplicate and their split tears will duplicate. Half of the tears fired through Multidimensional Baby retain The Parasite's look and the other half have the flashing appearance.
Haemolacria: Haemolacria shots will be duplicated and more burst tears will spawn. Burst tears that pass through Multidimensional Baby will also be duplicated.
Obsessed Fan/ Shade: Follows Isaac at the same delayed rate, in a way giving Multidimensional Baby contact damage.
Papa Fly: Papa Fly's path of movement is identical to Multidimensional Baby's, so the fly's tears will always be doubled.
Shooting familiars: Duplicates familiar's tears.
Sprinkler: Tears fired by the sprinkler can be duplicated.
Technology: When the laser passes through Multidimensional Baby, it doubles the laser.

???'s Soul/ Abel/ Cain's Other Eye: Familiar tears will be duplicated if they pass through the baby. However, due to their independent movement pattern, it can be hard to achieve duplication.
Anti-Gravity: Stationary duplicated tears will not launch with the rest of the tears when Isaac stops shooting and will stay stationary. Moving tears will be duplicated normally.
Baby-Bender: No effect as Multidimensional Baby only duplicates Isaac's tears.
BFFS!: The baby is larger, but tears shot through it will not do more damage.
Black Powder: If a small enough circle is drawn, the baby will follow and create a second circle overlapping it, doubling potential damage.
Box of Friends: Each copy of Multidimensional Baby follows the previous copy with a 2.5-second delay. Tears shot through multiple babies will only be duplicated once.
Compound Fracture: Tears that pass through Multidimensional Baby will be duplicated and cosmetically look like normal tears. Bone shards will not duplicate unless they pass through Multidimensional Baby separately.
Dr. Fetus: No effect.
Epic Fetus: No effect.
Lachryphagy: Duplicates tears, which tend to merge after traveling a certain distance, making it easier to feed tears. It does not duplicate burst tears.
Lil Brimstone/ Robo-Baby 2.0: Familiar lasers that pass through the baby will not be duplicated.
The Ludovico Technique: Spawns another tear that will slowly follow Isaac but cannot be controlled.
Mom's Knife: No effect.
Tech X: No effect.
Trisagion: No effect.

The way the tear splits resembles stimulated light emission.
In the initial release of Afterbirth, the flashing effect that Multidimensional Baby gave tears was much more intense, and made some players feel nauseous. This was changed in version v1.06.0052.

Bug! Switch Can double Best Friend when it passes through.

PC 3BGY TK8J (Treasure room adjacent to spawn, both modes)