The funeral rites used by ancient people to become Yamask after death have never been found in detail. What little archaeologists know implies that the world was better off having forgotten.

Cofagrigus has completely abandoned its old life to revel as king of whatever tomb it inhabits. Trainers exploring old ruins should bring a small amount of gold they can tribute to Cofagrigus. It won’t decide to let you leave, but you can run away while it eats the gold.

Yamask in Galar do not remember their past lives, as evidenced by Dream World research. The worlds that Yamask dream of are twisted fragments of epic tales, with no context to make sense of it all.

Archaeologists consider Runerigus a double-edged sword. While it is a living piece of history, it consumes historical artifacts to evolve. Unscrupulous archaeologists feed Yamask relics that would otherwise fetch low prices, selling off the resulting Runerigus for massive profit.