The majority of baby Pokémon were introduced after their first-stage evolutions, with the exceptions of Togepi and Riolu. To achieve evolution, the majority of baby Pokémon require maximized happiness. Others will evolve by level up, but as the generations passed more complex methods of evolution were introduced.
In the video game series, the only way to obtain most baby Pokémon is through breeding. On occasion, non-player characters will give the player an egg containing a baby Pokémon, and this Pokémon typically cannot be obtained in any other method, except for breeding. Generation III introduced the first baby Pokémon able to be caught in the wild: Wynaut on Mirage Island. In Generation IV, many other baby Pokémon were also available, relatively easily, in the wild. Players may still find it preferable to breed though, for the benefit of egg moves (as many baby Pokémon have very limited movepools).
Baby Pokémon all have one thing in common: they are unable to breed unless they evolve into one of their higher forms, and are all in the No eggs egg group. This is presumably due to their infantile state.
From Generation III onwards, most new baby Pokémon can only be obtained by making the parent in their evolutionary line hold a specific Incense before breeding, explaining why they were unavailable in previous generations.
About half of all baby Pokémon are part of a three-stage evolutionary line, that is, they evolve again after evolving from their Baby form. Only one of these, however, is achieved by level up, with most of the others requiring use of an evolutionary stone or held item to evolve a second time.
Baby Pokémon were eventually introduced in the Trading Card Game as well.
List of baby Pokémon
- All baby Pokémon, excluding those which evolve by level-up alone, are able to evolve at a minimum of level 2, as the requirements for their evolution can be met without them having to level up more than once.
- Of those that are able to do this and evolve a second time, only one (The Chancey line) must level to 3.
- Out of eighteen baby Pokémon, there are currently seven baby Pokémon which will evolve into Pokémon belonging to the Fairy Egg Group and six others that will evolve into Pokémon that belong to the Humanshape Egg Group.
- Of all post-Generation II baby Pokémon, only Azurill and Munchlax evolve by happiness alone (not requiring a certain time of day). These two baby Pokémon are owned by two of Ash's previous traveling companions, Misty and May.
- All baby Pokémon that were introduced in Generation II that evolve by happiness can evolve further using evolutionary stones.