Moon is a fat cat from Studio Ghibli's film Whisper of the Heart. He is Shiro Nishi's pet, technically, but he often runs away and drifts from house to house, being called by many names. He's a street cat and doesn't stay in one place.
He leads Shizuku Tsukishima to Shiro's shop, Chikyuuya.

Moon is also featured in the film The Cat Returns. In this he is called Muta, but has the same free spirit.