A while back I designed a 3D Mario mushroom from the Super Mario World original sprite design which was a really pain in the neck to make. Today I came across a much harder project that I can't even begin to figure out how the creator made it.
Super Giants Wing's 3D Super Mario Bros. Pipe is made completely out of Perler beads by the looks of it. From what I can see, the artist did various layers from different angles to complete the 3D, rather than going with one layered direction like my mushroom.
I love how the artist finished the piece off with Luigi trying to make his way down the pipe too. Very cute.