Skewbs: Oblique cubes
Strictly speaking, a Skewb is a shape mod of a Pyraminx. That’s because it too contains a mechanism with 4 axes which run along the space diagonals. Its special feature: The corner pieces can not be turned. Even though this may sound a little intimidating at first, Skewbs are actually easier to solve than the 3x3 cubes. Because these twisty puzzles have gained so much in popularity, a separate category for Skewbs was introduced at WCA competitions in 2014.