Tongueworm

This coil of muscle terminates in a sharp barb. When you attune to it, this daelkyr-bred tongueworm attaches to your throat and nestles under your tongue. You can use a bonus action to make an unarmed strike using the tongueworm, using your choice of Strength or Dexterity for the attack. On a hit, you deal piercing damage equal to 1d4 + your Strength or Dexterity modifier (your choice), instead of the bludgeoning damage normal for an unarmed strike. In addition, the target must succeed on a DC 13 Constitution saving throw or be poisoned until the start of your next turn.

Symbiotic Nature. The tongueworm can't be removed from you while you're attuned to it, and you can't voluntarily end your attunement to it. If you're targeted by a spell that ends a curse, your attunement to the tongueworm ends, and you can remove it.