Two of the six mice that I know of pair with a cat. Below is my pair. As you see, the mouse is on a longer base than the cat. This was done to accommodate its tail. It is not as pretty as the new mouse--in fact, when I bought it, it was described as a cat! As it makes for a very ugly cat, it was quite inexpensive. I got really, really lucky in that I later found the companion cat. At times, I think a Pottery God looks out for collectors, and finding the cat was one of those moments.
On the subject of mice, there is a mouse house in the Hunt Collection.
If you find a Staffordshire mouse, do not expect it to be inexpensive. There seems to be an inverse correlation between size and price, or perhaps it is rather that there is a direct correlation between cuteness and price. I doubt I will ever find a companion cat for the new mouse, but who knows?