At first glance, the tongueworm appears to be a small cobra with the same color as a human tongue. The tongueworm can enter the mouths of willing or helpless hosts, then bond itself to the top of the host's mouth. The tongueworm can then spring from its location hidden on the tongue of the user, launching itself out of the user's mouth and attack a creature using a poisonous barb. Like most symbionts, the tongueworm understands Undercommon, but can speak to its host telepathically once bonded. Once bonded, the tongueworm cannot be removed without the user taking damage. The tongueworm's reach is 5 feet, and its poison is designed to paralyze its prey. The tongueworm conveys an immunity to its own poison to its host.