Nidhogg’s Tooth

Wondrous item, very rare

This fist-sized serpent’s fang is carved from obsidian and is curiously cold to the touch.

You can use an action to place the fang in an unoccupied space within your reach or to throw it into an unoccupied space within 10 feet of you. Upon doing so, it burrows into the ground and vanishes.

A tveirherjar appears in an unoccupied space as close to where the fang vanished as possible. The tveirherjar is an ally to you, speaks all the languages you speak, and lingers for 10 rounds before disappearing.