Cats vs Cat Kingdom Cats

Never quite understood if the cat Kingdom Cats walking on two legs that are walking to meet Haru for the first time with the king, if they are different than the cats walking on four legs? Like are they bewitched or something, different from regular cats? Why do the regular cats get upset at them and try to attack them? If they are different as in magical and such then how did the little white kitten Haru feeds the crackers to become a part of the Cat Kingdom and be able to walk on two legs and talk?