A rare find!
This is a prototype Big the Cat plush. It was made by Tomy, but in the UK. (Tomy mostly operates in USA & UK, some of their stuff is dual-release) However, it was made FOR and to be released by Jazwares when they were getting into making plushes.

Notice the cloth tag says "TOMY". However, this never got made/won't get made. It's not very large, but seems to have decent detail. For some reason, companies to don't do too well at plush always seem to magically be able to make good Bigs, while they mess up everyone else. Look at the individual details for his head/hair spikes, notice the nice work on the tail tip & inclusion of all details like his sandals with buckles, belt, longer/different glove type & cheek fur/chest fur edges. This was seen at ToyFair 2010. You can spot it in the ToyFair viewing video at Youtube Toyfair Footage 2010. There is also a In Depth Showcase Footage to see.