Vampire Ring

Gain a little health every time you slay a monster.
Overview
The Vampire Ring is a ring that can be obtained as a reward from 

Its effect is simple and useful in combat: each monster slain restores 2 health. This makes it a reliable source of sustain during long mining runs, Skull Cavern expeditions, or any other activity where the player expects to fight many enemies. Because the healing triggers on each kill, it works best in areas with frequent enemy encounters rather than against isolated tough targets.
Effects from multiple Vampire Rings stack. If more than one is equipped, each ring separately restores 2 health per monster slain, allowing for higher total healing after each kill. This makes the ring especially valuable for players who want to reduce reliance on food while fighting through dense monster groups.
The Vampire Ring can also be used as a red dye in the dye pots located at 

Official description
Gain a little health every time you slay a monster.