Thomasin's Thunderbolt

An invisible javelin appears in the caster's hand and hurls itself toward a target within range, striking with the force of a thunderclap. Make a ranged spell attack against the target. On a hit, the target takes 1d6 piercing damage and 3d4 thunder damage, and it must make a Constitution saving throw, becoming stunned until the end of its next turn on a failed save. On a miss, the javelin's shock wave causes only half as much thunder damage and requires no saving throw.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the thunder damage increases by 1d4 for each slot level above 2nd.