Answer:
Well, the cat seems to have the ability to walk through some portal that allows him to go from the real world to the other world. I'm not sure if the other characters were able to do that. Also, his personality seemed to stay the same in both worlds. Except, in the other world, he can talk. The characters in the other world all have different personalities and characteristics apart from the ones in the real world. The cat, just doesn't seem to have changed except that he can talk in the other world.
Step-by-step explanation: