Melf's Acid Arrow

Make a ranged spell attack against the target.
On a hit, the target takes 4d4 acid damage
immediately and 2d4 acid damage at the
end of its next turn.
On a miss, the arrow splashes the target
with acid for half as much of the initial
damage and no damage at the end of its next turn.
3rd level or higher, the damage
(both initial and later) increases by 1d4
for each slot level above 2nd.