The ??? type is a type. It is also a glitch type. There are, as of yet, no official Pokémon with this type, but all Glitch Pokémon have this type. Eggs are also listed under this type, seeing as they have no type until they hatch. It exists in the generations from Generation II until Generation IV. It is not present in Generation V. Although it is not possible to make Arceus ??? type without hacks, it has a ??? type sprite. Zygarde, mainly core and cell have a ??? type as well.