From Bulbapedia, the community-driven Pokémon encyclopedia.
The Gender unknown Egg Group (Japanese: せいべつふめい Sex Unknown) is a pseudo-Egg Group, listing Pokémon which are genderless yet still able to breed.
The Gender unknown Egg Group is characterized by its members' lack of a gender. All members of this Egg Group are genderless yet are able to breed, but only with Ditto.
This group does not specifically exist in the games' programming, instead placing each Pokémon into other Egg Groups with Pokémon who have genders. Despite this, these Pokémon are not able to breed with other gendered or genderless Pokémon in their real Egg Groups, and this group is actually officially listed in Pokémon Stadium 2.
All Pokémon in this group are actually listed in other groups, as the Gender unknown Egg Group does not exist in the games' programming.
- If this Egg Group were counted as an official Egg Group, its members are the only Pokémon that can possibly belong to three Egg Groups (although currently, Phione, Manaphy and Carbink would be the only ones).
- A vast majority (25 of 30) of the Pokémon in this group are in the Mineral Egg Group.
- This is most likely because sediment is an inanimate object, therefore having no gender.