Pitbone Arrow

Ammunition, uncommon
  These crude arrows thrum with energy, ready to shatter upon impact. The flights—pitcrow feathers—are enchanted to flare when a target is missed, turning the arrow into the ground where it can erupt in a cloud of bone fragments. Hit or miss, these single-use arrows are a nuisance on the battlefield.
  Hit. When you hit with this arrow, the target must succeed DC 13 Constitution saving throw or have the shattered bone fragments lodged in obtrusive places within its body. On a failure, a creature takes 1 piercing damage when it moves for the first time on a turn and whenever it takes the Attack action. On a success, a creature is unaffected. As an action, an affected creature can make a DC 13 Wisdom (Medicine), ending the effect on a success.
  Miss. When you miss with a ranged attack using this weapon, the arrow changes direction to hit a surface near to the target, where it explodes into sharp fragments. Each creature within the target’s space (i.e. within 2 feet of it) must make a DC 13 Dexterity saving throw or take 1d4 piercing damage.
  Rare variant: Increase the damage of Hit to 2, and the damage of miss to 1d8. Increase the DCs to 15.
  Very rare variant: Increase the damage of Hit to 4, and the damage of miss to 2d6. Increase the DCs to 16.