Cold Crawl

You touch a surface causing ice to crawl across it. This ice occupies 4 10-foot squares on the surface you touch (including the surface of liquids). You can choose the arrangement of the spaces with the following requirements: at least 1 space appears where you cast the spell, and all spaces must have at least 1 face adjacent to another space. The ice can also crawl from 1 surface to another, and the spaces can be bent to accommodate the changing angles of surfaces as long as the requirements are met. When you cast this spell, any creature touching or standing on the ice must make a dexterity saving throw. Creatures that fail the save have their speed reduced to 0, cannot benefit from any additional movement speed, and take 2d6 piercing plus 2d6 cold damage; creatures that succeed take half the damage and are subject to no other ill effects. Any ground in this spell’s area effect becomes difficult terrain for the spell’s duration. A creature is immune to this spell's speed reduction if it cannot be grappled or if it cannot be restrained.

A creature that has failed a saving throw against this spell takes 2d6 cold damage at the end of each of its turns until it is freed or the spell ends. Said creature can attempt to free themselves by using their action to make an Athletics check, or another creature within reach can use their action to make an Athletics check against your spell save DC. 

This spell can be cast underwater or in a similar liquid. You can touch a space inside of the liquid, and the area of effect becomes 4 10-foot cubes, which must be within the liquid, rather than 10-foot squares.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, each instance of cold damage increases by 1d6 and the area of effect gains one additional 10-foot square for each slot level above 3rd.