Egg group
Egg group is a breeding category
There are 15 egg groups, including Ditto and Undiscovered. A species belongs to one or two groups. Undiscovered species, which include most legendary Pokémon and the baby Pokémon, cannot breed.
Main-series games; introduced in Generation II, Gold and Silver.
One later change
- Ruby and Sapphire's incense babies such as Azurill made the egg's species depend on a held item.