Here's another great rare item: Sonic & Knuckles Boots!
These are solid rubber rain boots, called Wellington Boots. Usually boots are such a plain thing, but the S&K symbol can make anything stylish! It's nice and big on the side of each one, with the name too, all done in shiny plastic. These are uncommon. 

In the gallary you can see some very similar shoes. This is a pair of clark-wellington boots from 1992. It was likely made before the S&K boots seen above, but they're still all-rubber to protect from the rain. The design consists of little 'screens' with pictures of Sonic's face on them. The Sonic face is the foreward facing one that was popular in the 1990s in the UK. It also has the Sonic logo at the top. The design for these is just ok...in that it is rather small compared to the boot and it looks like most of the detail went into the frame rather than adding more 'Sonic' to them. Still, these are a rather unusual collectible and are interesting to see. Photo by Scavenger4food.