Yooooo, so I was thinking about Cofagrigus and Yamask and how Cofagrigus eat gold and punish tombrobbers and worldwide cultural phenomena involving burying gold and precious metals and I came up with an interesting little theory.
So the Pokedex tells us that Yamask are spirits of the dead who remember their past lives and reminisce while looking at their eponymous masks. But where do they get these masks? There’s no evidence in canon that people bury their dead with golden masks of their faces, and, since the cultures and traditions of the people in Pokemon are largely based on real life, it is unlikely that people do so. So Yamask must either spontaneously create their own masks or perhaps get one from somewhere.
Now, have you heard of Charon’s obol? It’s the coin the Ancient Greeks would bury with their dead so that the ferryman would give them a ride to the afterlife. Except the practice of people burying coins and other valuable goods with the dead existed before the myth was created and exists in almost every culture.
SO… what if the gold buried with their corpses was what the masks are made out of? A Cofagrigus might use their Mummify ability to transform and coat the skulls after eating enough gold. The golden mask features a closer resemblance to the Yamask’s original human form and makes an excellent shield when compared to a skull. If it requires crushing the skull into a more amenable shape… well, sacrifices must be made.
And so the coin would allow safe passage into the afterlife since it would serve as a coating for the shield Yamask will use during its new life.
And actually, wild Yamask sometimes carry Spell Tags that could be the remains of the cotton cocoon their mask was made in!