Otiluke's Freezing Sphere

A frigid globe streaks from you to a point of your choice within range, where it explodes in a 60-foot-radius Sphere. Each creature in that area makes a Constitution saving throw, taking 10d6 Cold damage on failed save or half as much damage on a successful one.

If the globe strikes a body of water, it freezes the water to a depth of 6 inches over an area 30 feet square. This ice lasts for 1 minute. Creatures that were swimming on the surface of frozen water are trapped in the ice and have the Restrained condition. A trapped creature can take an action to make a Strength (Athletics) check against your spell save DC to break free.

You can refrain from firing the globe after completing the spell’s casting. If you do so, a globe about the size of a sling bullet, cool to the touch, appears in your hand. At any time, you or a creature you give the globe to can throw the globe (to a range of 40 feet) or hurl it with a sling (to the sling’s normal range). It shatters on impact, with the same effect as a normal casting of the spell. You can also set the globe down without shattering it. After 1 minute, if the globe hasn’t already shattered, it explodes.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each slot level above 6.