Acid spit

Once per day as an action, you can launch a glob of your venom at a target within 30ft as a ranged attack. On a hit, the glob deals 1d8 acid damage and 1d8 poison damage. The poison damage increases to 2d8 at 5th level, 3d8 at 11th and 4d8 at 17th level.
The target then needs to make a constitution saving throw or be poisoned for one minute. It can repeat the saving throw at the end of each of its turns.