Named after the inventor of the Rubik's Cube—Erno Rubik. The cube uses a series of simple, modular elements that can be endlessly rearranged into infinitely variable letterforms and other shapes.
There is also a typeface version of this which comes in four variations—Standard, Variable Width, Wavy, and Eclectic—which are intended to be used in combination with one another. Click here to download it. If you want to build your own characters to use you can download this Illustrator file, which has everything you need.