A Yamasks body is shadow-like, looking more like a shadow than a ghost. It has red eyes that have a tear-like shape on the bottom, resembling crying. They have two clawed hands. They hold a golden mask with a cat-like face on the front.
Luigi (Temporarily in Mortem)
Kirby (Temporarily in Mortem)
Pikachu (Temporarily in Mortem)
Link (Temporarily in Mortem)
Filia (Temporarily in Mortem)
Phantump- Phantump is a Pokemon introduced in generation 6. It has a much darker story than Yamask. It's Pokedex entry suggests it's a child who died in the woods. Phantump also follows the japanese myth of the Kodama. In SuperSpy Luigi, they inhabit Shy Guy Forest. The Eh... and You! Guys are unaware of this.
Cofagrigus- The evolution of Yamask becomes a much creepier Pokemon. Yamask becomes a coffin with sharp fangs and shadowy hands used to grab it's victims and tear them limb from limb. Only one Cofagrigus has appeared in SuperSpy Luigi. He was the king of an ancient land.
Carris- Carris is a Yamask that appeared in Season 13 of SuperSpy Luigi. Carris was found by Pikachu and Filia at Shy Guy Forest. He didn't know he was dead as he was searching for his father. Pikachu and Filia agreed to show him the way. Once he found out he was dead, the 2 led him to the afterlife. He was sad to leave his family, but he was greatful for Pikachu and Filia's help.