Hamster-Rat and Cat

I was on my bed and next to me was this little hamster - or rat? Hamster with a rat tail. At first it was black and white but it turned tan and white - and was rolling around on my pillow making itself comfy. I started talking to him, and he talked back. Later I was in the living room laying on my stomach on the floor. My new hamster-rat friend was behind the tv and decided to run out and there was a gray and white cat sitting 5 feet away. I screamed "Nooo! Run onto my back!" so it did and the cat lunged into the air. I blocked it with my arm - and it ended up with its fangs on my wrist. When it let go, I got up and put hamster-rat back into my room and shut the door. Shoved a carpet under the crack of the door because I wanted to hide him from the cat. I walked out of the room, and went to the bathroom. The cat followed me, and just sat in front of the door watching me. Green eyes. However he would roll his eyes all the way to the back of his head, revealing all whites and a tip of green on top. His eyes would roll back into his head, and then back to normal. Back into his head, and then dropped back to normal. Non-stop.