The Moro clan is a group of wolves living in the forest of the Forest Spirit. Not much is known about the clan as a whole aside from their duty in protecting the forest and by proxy also guard the Forest Spirit. Only four members of the clan are seen, and it is not mentioned whether or not there are more. The four members are Moro herself, Moro's two (unnamed) pups, and San (Moro's adopted human child).
The clan may have once had a partnership with the Boar clan, and may have fought alongside them once before the events in the film.