So I just noticed that the Rex Cube and Face-Turning Octahedron are literally the same puzzle, just a shape mod apart. And the only thing that separates both of these from the Master Skewb is the lack of the parts that equate to the Master Skewb's corners. I know how to solve the Rex, but never figured out the other two...until now. What other very visually-distinct puzzles do you know of that are actually the same thing?

The mastermorphix and 3x3, the megaminx and hexaminx, the pyraminx, skewb, skewb diamond, and skewb ultimate...the list goes on and on. I think what baffled me the most was that the Ghost Cube was identical to a 3x3.

I got the mastermorphix back when I was a noob, and it took me months to realize that it was a 3x3. At one point I had back in its proper shape and was trying to solve it with U2 R2 etc. Needless to say, it did not work.

some of the more interesting puzzles that are mechanically the same come in the form of dodecahedra transformed into icosahedra.

Most shape variants are "Super"-variants of the original puzzles => They share the same solution although the shape variant often requires reorientation of pieces the original puzzle does not.

Once I started to classify all puzzles in unified system:
viewtopic.php?p=190396#p190396
All puzzles which share the same signature according to that system share the same solution.

Andreas