A client of mine wanted a surprise Super Mario cake for her boyfriend's birthday. She said that she "googled" his favourite character, Shy Guy Red, but no cake pictures had come up.
I did the same and she was right - no Shy Guy Red. However, I found some very cool websites and some awesome Super Mario cakes posted all over the internet. Here's a link to a site called Geekologie with lots of amazing "geek" cakes including Super Mario ones.
And of course, here is the Shy Guy Red vanilla cake with swiss meringue buttercream covered in fondant. Characters are handmade out of sugarpaste.