First up, the Plumbers who never actually do any Plumbing! You will need: A 3DS An SD card Also, try clicking Mario's QR code.
All of these characters belong to Nintendo. I'm planning to do more of these, I can take requests, although if they are very complicated, I may not be able to make the requested Mii. I'd prefer if you put requests here: http://scratch.mit.edu/studios/616110/ because it will probably be much easier for me to find them there.