I like how my autobots magnet came out, but not so pleased with the decepticons.
How I went about making them:
First I drew pixel art in photoshop, then I made a grid outline which I then used as the template for my perler board.
(oh and I bought magnets from the local craft store. just peel off the sticky backing and attach to one side.)
For your ease of reference, should you yourself want to make these... here are my grids: