Ok theory. These cats are the same colors as playable characters in the base Super Mario 3D World. So what if the story is that all characters except for Mario have been turned into real cats and only Mario can save them?

red cat?

that's pink

nah that is definitely red

this is red

yeah that's the same colour

eyes

Its not as shaky on Discord, I didn't realize how fast it goes when I upload the gif on twitter :3

no i mean that is the answer to your question