Is It a Cap, a Put, or a Cup?

If you have a pet that is half cat and half pup, what do you have? Ah, I hear the sceptics saying there is no no such creature. I beg to differ. This thing looks like a cat, sounds like a cat, sleeps like a cat, acts like a puppy.

He follows me around, up and down 2 sets of stairs. He stands on his back legs for at least 6 or 7 seconds (counted), and chases his favorite toy (a shoestring) down the stairs, and carries it back up, dropping it at my feet. This happened over and over, at least 30 times, until ONE of us got tired of the game.

And along with these peculiarities, he is extremely conversational, with a wide range of easily interpreted sounds. So what would YOU call this creature?