Erupting Geyser

A torrent of scalding water bursts forth from your gaping maw. Make a ranged spell attack against a creature within range. On a hit. the target takes 1d10 fire damage and 1d8 piercing damage, and the target must also succeed on a Constitution saving throw or become exhausted until the start of your next turn. 

At Higher Levels. When you cast this spell using a spell slot of 3rdlevel or higher, the piercing damage increases by 1d8 for each slot level above 2nd.