Belt of Dwarvenkind

From Dungeon Master's Guide, page 155. Found on Magic Item Table G.

Description
Wondrous item, rare (requires attunement).

While wearing this belt, you gain the following benefits:
 * Your Constitution score increases by 2, to a maximum of 20.
 * You have advantage on Charisma (Persuasion) checks made to interact with dwarves.

In addition, while attuned to the belt, you have a 50 percent chance each day at dawn of growing a full beard if you're capable of growing one, or a visibly thicker beard if you already have one.

If you aren't a dwarf, you gain the following additional benefits while wearing the belt:
 * You have advantage on saving throws against poison, and you have resistance against poison damage.
 * You have darkvision out to a range of 60 feet.
 * You can speak, read, and write Dwarvish.