'M is a dual-type Bird/Normal glitch Pokémon, often called the "sister" glitch counterpart to Missingno., due to sharing a sprite and Pokédex number, and is found exclusively in Pokémon Red and Blue. Although similar to Missingno. at first glance, the two are separate glitch Pokémon with many differences. They have different index numbers, causing differences such as 'M having the ability to evolve into Kangaskhan and Clefairy while Missingno. cannot. The similarities that they have are a result of coincidentally sharing a Pokédex number.