Source: Tasha's Cauldron of Everything

Wondrous item (tattoo), very rare (require attunement)

Produced by a special needle, this magic tattoo features symbols of life and rebirth.

Tattoo Attunement. To attune to this item, you hold the needle to your skin where you want the tattoo to appear, pressing the needle there throughout the attunement process. When the attunement is complete, the needle turns into the ink that becomes the tattoo, which appears on the skin.

If your attunement to the tattoo ends, the tattoo vanishes, and the needle reappears in your space.

Necrotic Resistance. You have resistance to necrotic damage.

Life Ward. When you would be reduced to 0 hit points, you drop to 1 hit point instead. Once used, this property can't be used again until the next dawn.