Vipers of Valtorr

A line of vaporous poison snakes 60 feet long and 5 feet wide emanates from you in a direction you choose. All creatures in the area must make a Constitution saving throw, taking 3d6 poison damage on a failure or half damage on a success.

The snakes cling to creatures who failed their saving throws, violently biting to inject their vaporous poison. Whenever such a creature takes an action in its turn, it must make another Constitution saving throw, taking another 3d6 poison damage on a failure. The snakes remain on a creature as long as it takes poison, acid or necrotic damage before the end of its next turn, regardless of the saving throw result. Otherwise, the snakes disappear in vaporous hissing on a success.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.