Playful Puss (1953)

As Percy, the cat, is chasing Little Roquefort, the mouse, a small pussycat appears at the front door, and Percy tries to make it an ally. However, the playful pussy likes Roquefort as a playmate, and they team up against Percy. Finally, Percy's mistress, givers his bed to the newcomer, and he shares it with his newly-acquired mouse friend.