Isaac's Heart

Isaac's Heart is a secret unlockable passive item.

Effect

 * Isaac's body becomes immune to all damage.
 * A heart familiar appears and closely follows Isaac. If the heart is hurt, Isaac is hurt.
 * Most enemies now target the heart instead of Isaac. Eyes and other similar enemies, however, will still target Isaac.

Synergies

 * - Isaac can cause contact damage without taking damage.
 * - Isaac can use Blood Rights infinitely without taking damage.
 * - Isaac can be infinitely invulnerable, as invincibility carries out to the heart without hurting the player. Note that the item needs to be activated for longer than one second for the invulnerability to kick in, however.
 * + XIV - Temperance - Isaac can reuse the Temperance card to get effectively infinite money.
 * - If Isaac's Heart is layered over Dry Baby, Dry Baby will block incoming shots and the heart will not be damaged by projectiles. Enemies touching the heart can still do damage.
 * : Isaac's Heart will stay in place relative to Isaac.
 * - Isaac can turn enemies into poop without taking damage.
 * : Isaac's Heart and Isaac will occasionally be connected via electricity.
 * - Invincibility carries over to the heart.
 * - The shield effect carries over to the heart.
 * - Isaac can use the bag without taking damage, granting infinite money.
 * - As long as the heart is away from the blast radius, no damage is taken. Character must be at high enough speed for this.
 * - Isaac can turn enemies into coins on contact without taking damage.
 * - Isaac cannot take damage from the Razor Blade, allowing for infinite uses of the item.
 * - Demon Isaac can cause contact damage without taking damage.
 * - Isaac can poison enemies on contact without taking damage.

Interactions

 * - Box of Friends does not duplicate the heart.
 * - BFFS! will make the heart bigger, making it easier to get hit.
 * : Familiar will stay in place relative to Isaac.
 * - The Heart will follow King Baby. This makes it much harder to avoid damage, but also makes other synergies like Kamikaze! much easier to use.
 * - Sharp Plug can no longer be used.
 * - Isaac's body repels projectiles, but Isaac's Heart doesn't.

Trivia

 * Isaac's Heart while it's following Isaac fittingly shares the same sprite as.
 * The nature of the item is similar to that of a Mask + Heart enemy.
 * This item is used in Challenge #30 (The Guardian).

Seeds
TPWZ 7CVR (Treasure Room below of spawn) PCJZ 03TG (Adjacent Treasure Room) W1TD 0BJN (Treasure room south of spawn)

Gallery
Isaac's Heart