Yamask

Using Yamask in a Playthrough

Ordinary Yamask evolves into Cofagrigus at level 34, while Galarian Yamask follows a unique route to Runerigus: after taking at least 49 HP of qualifying damage without fainting, it must pass beneath a specific stone arch or equivalent landmark. Cofagrigus is pure Ghost with base 145 Defense, 105 Special Defense, 95 Special Attack, and only base 30 Speed, making it excellent for Trick Room, Will-O-Wisp, Shadow Ball, Nasty Plot, Hex, Toxic Spikes in later games, and physical walling. Its Mummy ability replaces the Ability of a Pokemon that makes contact with Cofagrigus, which can disable dangerous effects such as Huge Power, Guts, or other contact-dependent offensive advantages. Runerigus is Ground/Ghost with the same 58/145/105 defensive core but base 95 Attack instead of Cofagrigus's 95 Special Attack; Earthquake, Poltergeist or Shadow Claw, Stealth Rock, Toxic Spikes, Will-O-Wisp, and Trick Room suit its physical profile. Wandering Spirit swaps Runerigus's Ability with that of an opponent that makes contact, producing more complex interactions than Mummy. Quiet is excellent for offensive Trick Room Cofagrigus, while Impish or Careful suit defensive Runerigus.

Yamask in Competitive Pokémon

Cofagrigus was a strong BW UU Pokemon because its base 145 Defense and Ghost typing made it one of the tier's most reliable answers to powerful Fighting-types while simultaneously blocking Rapid Spin. Mummy weakened physical attackers that relied heavily on their abilities, and Cofagrigus was not purely passive: base 95 Special Attack, Nasty Plot, Shadow Ball, Hidden Power Fighting in the era, and Trick Room supported a dangerous offensive set in addition to defensive Will-O-Wisp builds. Runerigus inherited the same extraordinary physical Defense but shifted into a Ground/Ghost utility role with Stealth Rock, Toxic Spikes, Earthquake, and Wandering Spirit. Smogon places Runerigus in SS ZU and notes that its excellent physical bulk and wide support movepool are offset by five common weaknesses and the absence of reliable recovery, leaving it easier to wear down than the defensive stats suggest. The family therefore contains two related but strategically distinct walls: Cofagrigus is the stronger special attacker and historical spinblocker, while Runerigus offers Ground STAB, an Electric immunity, hazards, and ability-swapping utility.

Yamask in Nuzlockes

Cofagrigus is one of the safer physical walls available in a Nuzlocke because base 145 Defense, Normal and Fighting immunities, and Mummy can neutralize dangerous contact-based abilities. Its base 58 HP is much lower than the defenses imply, however, and strong Dark or Ghost attacks can still break through quickly; recovery is also limited compared with dedicated walls that have Recover or Slack Off. Trick Room can turn base 30 Speed into an advantage, but the safest use is usually Will-O-Wisp, reliable Ghost damage, and deliberate immunity switches. Runerigus adds an Electric immunity and Rock resistance but gains weaknesses to Water, Grass, Ice, Ghost, and Dark, so its Ground/Ghost typing is more matchup-dependent. The evolution requirement for Galarian Yamask is itself risky under permadeath rules because it must accumulate at least 49 HP of attack damage without fainting, so the process should be performed against carefully selected weak opponents rather than during an important battle.

Unovan Yamask is said to arise from the spirit of a human buried in a grave long ago. It retains memories of its former human life and carries a golden mask shaped like the face it once had, sometimes staring at that mask and crying. Yamask becomes furious if the mask is taken away and may wander ruins searching for someone who recognizes its former face. In animation, a human wearing the mask can even be possessed by the Yamask.