Frigid Grasp

You conjure a ball of unnaturally cold ice and hurl it at a target. Make a ranged spell attack roll. If it is successful, the target takes 3d6 cold damage, and if the target is a creature that is large or smaller, it must succeed on a Strength saving throw or be restrained by magical ice until the spell ends. A creature restrained by the ice can use its action to make a Strength check against your spell save DC. On a success, it frees itself. If an unoccupied liquid is hit by this spell, a 5-foot cube of it, centered on the point of impact, freezes solid for the spell's duration. 

At Highr Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for each slot level above 2nd, and the size of a creature you can restrain with this spell increases by 1 size category for every 2 levels above 2nd.