| Floors of
| The Womb|
| Base Health||950|
|Unlocked By||Defeat Mom's Heart 11 Times.|
It Lives performs many actions during the fight, but she performs some before the others. The actions she performs first are as follows:
- It Lives will spawn two Eyes. It will be in full view of Isaac.
- It Lives will spawn two more Eyes one by one after the first two are killed. It will also shoot patterns of tears during this phase and will hide from Isaac.
Next, It Lives will perform one of the following actions:
- It Lives will shoot patterns of tears at Isaac, the speed of the tears increasing as its health diminishes.
- It Lives will shoot brimstone lasers out of all four cardinal directions and spin the beams around.
- It Lives Heart will spawn a variety of common Monsters throughout the fight.