Here's something probably impractical. It is a key cap, but it's too big to be practical. Look at the size of the key compared to the cap. This wouldn't fit in a pocket & would 'hog' a key chain. Maybe a purse or a school bag? Either way, it is a down-sized version of the "Classic Sonic Wii Mote Remote Holder" figure. They added a GHZ style cube base to insert the key top, and added a spring loaded key clip to Sonic's head to turn this into a keychain item.
But then, to use the key, you have to grip the figure and turn it that way? It would actively make any key harder to use. This would probably be best if left as a little display figure rather than for active use. It is slightly strange. It can likely be bought at Smyth's stores in 2020.