Mom's Heart is the final boss of The Womb II. In the beginning of the battle it is always accompanied by two Eyes. If you listen closely to its theme song, you can hear heart beats.
Mom's heart spawns two to four monsters and then disappears. After killing those monsters, the heart will reappear in the middle of the room for 3-4 seconds, spawn more monsters, then disappear again. If you manage to kill the monsters within two seconds from their spawning (before the Heart disappears), Mom's Heart will stay on screen and spawn a next pack.
Provided you have bombs, placing a bomb just as the heart is about to drop into vision will not only damage the heart, but may also destroy any monsters the heart spawns; this can afford you essentially double the attack time against the heart.
When Mom's Heart drops down to 33% health, it will stop hiding but continuously spawn monsters and start firing bombs similar to those fired by Sloth and other monsters. The explosions will leave glowing puddles of blood, similar to the ones left by the brains, that do damage on contact and last for several seconds. The monsters it spawns in this phase are usually weaker, consisting largely of various small flies.
Alternatively, using The Bible will act as an instant kill, similar to using it on Mom. This is not to be confused with the similar looking 'Book of Revelations' item which has no effect on Mom or Mom's Heart.
Also items such as the My Little Unicorn and the Gamekid do not work on it, but those items may be useful to fight the monsters it spawns.
After you defeat Mom's Heart nine times, it is replaced with It Lives.
- When defeating Mom's Heart using the Bible, the health bar will not disappear, but the game will go on with the ending as usual and the chest will appear (seems to have only appeared since The Wrath of the Lamb was released)
- The firing bombs, similar to those fired by Sloth, can get you out of the map and then you will be unable to finish the game (because you are stuck in an invisible wall).
- If you are in the Womb XL or Utero XL, then the boss right before Mom's Heart/It Lives! will also play the heart's music, and Mom's Heart/It Lives! will still play its own music. This also occurs with Mom in The Depths XL and Necropolis[XL].
- Audio: If Mom's Heart or It Lives is taking multiple hits of damage right before it starts firing bombs, many occurances of it saying "Isaac!" happens.
- If you kill yourself after defeating Mom's heart, but have a respawn item (1up, Ankh, Guppy), when you return to the room, mom's heart will have returned, but the chest is still there. You must wait for the heart to rise back up before running into the chest. The game goes on normally after opening it.
- If Mom's Heart or It Lives is damaged enough to start firing bombs before it comes down from the roof (via The Candle), it will stay on the roof and its shadow will remain, but bombs will still be fired from the center of the room.
|Basement||Larry Jr. • Monstro • The Duke of Flies • Gemini • Steven • Famine|
|Cellar||Widow • Pin • The Duke of Flies • Famine • Gurdy Jr. • The Blighted Ovum|
|The Caves||Fistula • Peep • Gurdy • Chub • C.H.A.D. • Pestilence|
|Catacombs||The Husk • The Hollow • The Blighted Ovum • The Carrion Queen • Peep • Pestilence • The Wretched • Gurdy Jr.|
|The Depths||Loki • Monstro II • Gish • War • Mom|
|Necropolis||Mask of Infamy • Daddy Long Legs • The Carrion Queen • The Bloat • Loki • War • The Wretched • Mom|
|The Womb||Scolex • Blastocyst • The Bloat • Death • Conquest • Daddy Long Legs • Triachnid • Teratoma • Mom's Heart • It Lives|
|Utero||Teratoma • The Bloat • Death • Conquest • Daddy Long Legs • Triachnid • Lokii • Mom's Heart • It Lives|
|Sheol||The Fallen • Satan|
|First to fifth and seventh level||The Fallen • Headless Horseman|