Runerigus's main body is composed of an oblong, irregularly-shaped slab of rock, with an outline of a stylized serpent with sharp teeth painted onto it in red. Two sections of the slab at the upper left and upper right side, along with a piece bearing the serpent's head and a small piece bearing the tip of the image's tail, have broken off and are held in place by shadowy black tendrils that form its arms, neck, and tail respectively; the "tail" fragment also resembles the piece carried by GalarianYamask. It has five black fingers on each hand, which extend from the ends of the fragments forming its arms. It has a single purple eye located in the same spot as the painting's eye.
Runerigus was formed from a painting imbued with an ancient curse, which was activated by absorbing the spirit of a Yamask and brought the painting to life. Anyone that touches its shadowy body will have the memories behind its painting's creation forced onto them.
In the anime
In the manga
In the TCG
This Pokémon was unavailable prior to Generation VIII.
Runerigus may be based on the Ingvar runestones, large stones engraved by Vikings used to commemorate the lives of notable people and events such as the Swedish Viking expedition to the Caspian Sea. Many of the rune stones discovered had a snake motif. Rune stones were also believed to have mystical properties that conveyed powers of protection, wealth, and victory. It may also be based on Apophis, the Egyptian God of chaos, who was often represented as a serpent.
Runerigus may be a combination of rune and egregious or Cofagrigus.
Desubān may be a combination of death, 板 ban (slab), and Desukān.