Troll Skin Armor
Armorrare
While wearing troll skin armor, you gain a +1 bonus to AC, and you stabilize whenever you are dying at the start of your turn. In addition, you can use an action to regenerate for 1 minute. While regenerating, you regain 2 hit points at the start of each of your turns. The armor can't be used this way again until the next dawn.
Source: Vault of Magic · OGL-1.0a · 5.1