It Lives is an unlockable alternative form of Mom's Heart. After being unlocked, it will always appear as the boss of the second floor of the fourth chapter, permanently replacing Mom's Heart. It is a stronger version of Mom's Heart that summons bosses alongside regular chapter 4 enemies.

Despite being a major boss, It Lives doesn't belong to any Ending. instead, it opens up entrances to both Sheol and the Cathedral, as well as ??? if beaten in under 30 minutes.

It Lives behaves exactly like Mom's Heart, except that it spawns Knights instead of Swingers and it spawns bosses from previous chapters, three in particular:

It also shoots some double projectiles when retreating upwards after spawning enemies/bosses.

It Lives ingame.

It Lives as one of Delirium's forms.

Just like Mom and Mom's Heart, using The Bible against It Lives will kill it instantly.

Isaac can still encounter It Lives in the nightmare boss wave of chapter 4 in Greed/Greedier mode if it has not been unlocked.

It Lives appeared in the original The Binding of Isaac.

The music that plays during this fight is titled Ventricide . [1] Ventricide is a made-up word formed from the word ventricle (chamber of the heart) and the suffix -cide, which denotes an act of killing. This theme is used in other tracks, such as Matricide, Hericide, and Infanticide. Ventricide could also be a junction of the prefix ventr-, which could denote "belly", "stomach", or "womb" with the suffix -cide.

. Ventricide is a made-up word formed from the word ventricle (chamber of the heart) and the suffix -cide, which denotes an act of killing. This theme is used in other tracks, such as Matricide, Hericide, and Infanticide. It Lives, according to the developers, takes the shape of what Isaac looked like as a fetus.

It Lives makes the same sounds as Mom's Heart. Like Mom's Heart, if Isaac takes damage from It Lives' Brimstone

The unlock note for It Lives states "Your futures past awaits.", referencing Time Fcuk , another game by Edmund Mcmillen.

, another game by Edmund Mcmillen. During the versus screen, It Lives' enemy/boss-spawning sound can be heard. It Lives is one of six bosses that can be heard during the versus screen, the other five being The Stain, The Forsaken, Big Horn, Mom and Mom's Heart.

Bug! Sometimes, if the boss intro is skipped, the game will not teleport Isaac into the center of the bottom of the room, resulting in immediate contact damage with one of the Sometimes, if the boss intro is skipped, the game will not teleport Isaac into the center of the bottom of the room, resulting in immediate contact damage with one of the Eyes or It Lives, depending on the direction of the room's entrance.



