Pentacube
A polycube composed of 5 cubes. There are 29 distinct three-dimensional pentacubes. Of these, the 12 planar pentacubes (corresponding to solid pentominoes), are well known. Among the nonplanar pentacubes, there are five that have at least one plane of symmetry; each of them is its own mirror image. The remaining 12 pentacubes come in mirror image pairs.