The withered ventricles and chambers of this dull grey heart do not tell much of a story about the creature that it came from. Surely any creature missing a heart must be long from this mortal coil? Surely...

When you attune to this heart it swaps itself with your living heart.

• Your living heart beats outside your chest.
• If your living heart is damaged, it uses your full hitpoint pool as its hitpoints, and has an AC of 6.
• If your body is destroyed, you live on (in some shape)
• If your heart is destroyed, your body dies.

You cannot break this attunement with normal means.

Notes: living creature.