Caustic blade

Evocation cantrip
Casting Time: 1 action
Range: Self (5-foot radius)
Components: V, M (a melee weapon)
Duration: Instantaneous
As part of the action used to cast this spell, you must
make a melee attack with a weapon against one
creature within the spell’s range, otherwise the spell
fails. On a hit, the target suffers the weapon attack’s
normal effects, except that any damage dealt by the
attack is acid damage instead of its normal type. If
you miss by 3 or less, acid splashes on the target, and
you instead deal 1d8 acid damage.
This spell’s damage increases when you reach
certain levels. At 5th level, the melee attack deals an
additional 1d8 acid damage to the target on a hit,
and the acid damage dealt on a miss increases to 2d8.
Both damage rolls increase by one die at 11th level
(2d8 and 3d8) and 17th level (3d8 and 4d8).