Cube

a 5-foot cube of a mysterious, gelatinous material for each expended charge. Each cube appears in an unoccupied space within 5 feet of you or adjacent to another cube you create as part of this action. The cubes are translucent objects that have AC 10, 20 hit points, and resistance to acid damage. Creating a cube in a space smaller than 5 feet across causes the cube to squeeze and fit the space. A cube remains for 1 minute or until it's reduced to 0 hit points, after which it dissolves into a puddle of slime and vanishes.

You can climb or walk on the cubes. However, their sticky surfaces are considered difficult terrain.