Popular Estonian children's book from the 60s in animation: when her older brother leaves, a 6 year old girl is given a magic doll with whom she gets to share some exciting adventures.
The little Calavera duo, Finado and Moribunda, must leave their comfort zone away from Pueblo Calaca when a human infant crosses the Eternal Mirror, absorbing energy from a portal that separates the Realms from the living and dead.