Egg Groups decide which Pokémon can breed with each other. There are 15 of them. Two Pokémon can make an Egg if they share at least one Egg Group and are of opposite genders. Ditto has a group of its own and can breed with almost anything, while Pokémon in the No Eggs Discovered group can't breed at all.
Egg Groups came in with breeding in Generation 2 (Gold and Silver). A Pokémon belongs to one or two groups, much like it has one or two types. You can see a Pokémon's Egg Groups on its page in our Pokédex.
All 15 Egg Groups
These counts are from our data for all 1,025 species. A Pokémon in two groups is counted in both, so the column adds up to more than 1,025. The names are the ones the games use.
| Egg Group | Species | Examples |
|---|---|---|
| Field | 278 | Rattata, Ekans, Pikachu, Eevee, Wailord |
| No Eggs Discovered | 151 | Pichu, Cleffa, Igglybuff, Articuno, Zapdos |
| Water 1 | 114 | Squirtle, Psyduck, Dragonite, Manaphy |
| Bug | 91 | Caterpie, Butterfree, Weedle |
| Grass | 89 | Bulbasaur, Oddish, Gloom |
| Mineral | 84 | Geodude, Magnemite, Shedinja |
| Monster | 81 | Bulbasaur, Charmander, Snorlax |
| Flying | 73 | Pidgey, Spearow, Fearow |
| Dragon | 72 | Charmander, Ekans, Magikarp |
| Human-Like | 70 | Abra, Machop, Lucario |
| Fairy | 66 | Pikachu, Clefairy, Skitty |
| Amorphous | 63 | Grimer, Gastly, Gengar |
| Water 3 | 37 | Tentacool, Shellder, Krabby |
| Water 2 | 34 | Goldeen, Magikarp, Wailord |
| Ditto | 1 | Ditto |
The groups are loosely based on what a Pokémon looks like. Bulbapedia describes Water 1 as amphibious Pokémon, Water 2 as fish-like ones and Water 3 as Pokémon that look like sea invertebrates. The fit is rough, though. Ekans is in the Dragon group, and so is Magikarp.
Pokémon with two Egg Groups
In our data, 279 species belong to two groups and 746 to one. The most common pairs are Field with Water 1 (25 species) and Monster with Dragon (21).
Two-group Pokémon link groups that would otherwise never meet. Pikachu is in Field and Fairy, so it can breed with Eevee (Field) and with Clefairy (Fairy). Players use these links to pass Egg Moves from one family to another across several generations of Eggs, which is called chain breeding.
The odd couples
Because Field is so big, some pairings look silly. The best known is Skitty and Wailord. Skitty is a small kitten and Wailord is a 14.5-metre whale, but both are in the Field group, so the game allows it. Bulbapedia uses that very pair as its example of an odd match.
A few more from our data:
| Pokémon | Egg Groups |
|---|---|
| Charmander | Monster, Dragon |
| Squirtle | Monster, Water 1 |
| Lucario | Field, Human-Like |
| Gardevoir | Human-Like, Amorphous |
| Magikarp | Water 2, Dragon |
| Dragonite | Water 1, Dragon |
| Snorlax | Monster |
The Ditto group
Ditto is the only Pokémon in its group. It can breed with any Pokémon outside the No Eggs Discovered group, whatever the gender, and that includes Pokémon with no gender at all. It can't breed with another Ditto.
That makes Ditto the only way to breed genderless Pokémon. In our data, 155 species are genderless. Forty of them can still breed with a Ditto, among them Magnemite, Porygon, Beldum, Rotom and Carbink. The rest are in No Eggs Discovered.
It also helps with Pokémon that are always one gender. Tauros, Hitmonlee and Gallade are always male (26 species in our data), so they need a Ditto or a female partner from another species in their group to make an Egg. The Egg hatches into the mother's family, so with a female partner from another family you get her species, not his. Volbeat and Illumise are a special pair: an Illumise mother can hatch either one.
No Eggs Discovered
Pokémon in this group can't breed with anything, not even Ditto. In Pokémon Stadium 2 it was called "No Eggs", and some sites still use "Undiscovered".
In our data the group has 151 species:
- All 71 Legendary Pokémon and 21 of the 23 Mythical Pokémon.
- All 11 Ultra Beasts and all 22 Paradox Pokémon (Koraidon and Miraidon are also Legendary, so they are in the first count).
- All 19 baby Pokémon. They can't breed until they evolve.
- Nine others: Nidorina, Nidoqueen, Unown, the four Galar fossils (Dracozolt, Arctozolt, Dracovish, Arctovish), Gimmighoul and Gholdengo.
The two Mythicals that can breed are Manaphy and Phione, both in Water 1 and Fairy. They have no gender, so they only breed with Ditto, and the Egg hatches into Phione. Phione never evolves into Manaphy.
Exceptions inside families
A family normally shares its Egg Groups. Bulbapedia names the exceptions: baby Pokémon, Nidorina and Nidoqueen, and Shedinja.
Nidorina is the strangest. Nidoran female can breed, Nidorina and Nidoqueen can't, and the male side (Nidorino is in Monster and Field) can. Shedinja is in Mineral rather than its family's Bug group, and it can only breed with Ditto because it has no gender. The Egg hatches into Nincada.
How to use this
When you want to breed a Pokémon, check its Egg Groups first. If it shares one with a Pokémon you already have of the opposite gender, you can breed them. If not, use Ditto. The Egg always hatches into the first stage of the mother's line, or of the non-Ditto parent's line.
The full breeding steps, including Day Care and picnic rules, Egg Moves, IVs and Natures, are in how to breed Pokémon. Some babies only hatch when a parent holds an incense, and the list is in baby Pokémon.