The Gigaminx (5x5x5), is one of the Megaminx's higher-order variations. Similarly to the Megaminx, it is a face-turning dodecahedron-shaped twisty puzzle. The difference is the amount of "layers" each face has (2 instead of 1 in the Megaminx) resulting in no less than 132 center pieces, 20 corner pieces, and 90 edge pieces. It was invented by Tyler Fox in 2006 however mass production of this puzzle only started in 2009.
Solving the Gigaminx is quite similar to solving the Professor's Cube (5x5x5) only a bit more tedious and repetetive. The good news are tough, this puzzle has absolutly no "parity cases" (the Professor's Cube has one edge parity case). One recomended method for solving it is the famous "reduction" method. First solve the pentagon center of each of the faces, then group the edges together and finally solve like a regular Megaminx.
The Gigaminx is not an official WCA puzzle however the unofficial record for fastest solve is 6:35.01 minutes set by Sam Myung of the United States.