Deadly Sting

8th-level transmutation (dragon)

Casting Time: 1 action
Range: Self
Components: V, S, M (a thorn)
Duration: Concentration, up to 1 minute

You grow a 10-foot-long tail as supple as a whip, tipped with a horrible stinger. During the spell’s duration, you can use the stinger to make a melee spell attack with a reach of 10 feet. On a hit, the target takes 1d4 piercing damage plus 4d10 poison damage, and a creature must make a successful Constitution saving throw or become vulnerable to poison damage for the duration of the spell.