PHB

Ray of Sickness

1-level Necromancy

A ray of sickening greenish energy lashes out toward a creature within range. Make a ranged spell attack against the target. On a hit, the target takes 2d8 poison damage and must make a Constitution saving throw. On a failed save, it is also poisoned until the end of your next turn.
At higher levels: When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.