Rat Clan: Marley/Origin

Origin
The Rat Clan Henchman derives from a Rat Youkai. Though, there aren't many specific information on rat youkai, or anything about them, but they have the regular abilities that a youkai has, like shape-shifting, human speech, and a taste for humans. The closest thing to a rat youkai would be the Tesso, which is a monk that turned into a monk and ate all the documents in Japan.