Dead Ringer

Alter: This bronze mask lets out a deep, sonorous ring when struck. When you're reduced to 0 HP or fail a death saving throw while wearing the mask, the 3 enemy creatures nearest to you within 30 feet must succeed on a DC 15 Wisdom saving throw or take 2d12 necrotic damage. This property has no effect on creatures who aren't missing any HP or are deafened. If you're healed or stabilized after falling to 0 HP, the mask cant be used again in this way until the following dusk.

Attunement: no
Rarity: Rare
Type: Helmet
Cost: 2655gp

Griffons Saddlebag, Vol 1