Accompanying Momo is a talking black cat familiar named Daniel, with a bell around his neck and bat-like wings who helps Momo out. The living frequently hear the ringing of Daniel's bell when Momo and Daniel are nearby. Daniel has a calm character and does not show as much sympathy to humans as Momo, but is still patient with them. In the TV drama, Daniel is portrayed as a young boy rather than a cat.
-Wikipedia