Dr. Kobold's Maddening Needle

Straight from the pint sized physicians own machinations you draw out a thin ethereal needle and launch it at your foe. The target must succeed on a wisdom save against your spell DC. On a failed save the target begins rabidly itching and writhing on the ground prone they suffer 1d4 psychic damage and for one hour an additional 1d8 slashing damage as they viciously claw at their own body. If a creature succeeds they take no damage and suffer no conditions from this spell. 

The creature can attempt the save on their turn, if they fail 3 consecutive times the effect is permanent for the whole one hour duration.

At level 5,11,and 17 the caster can launch an additional needle at a new target.