Alolan forms were introduced by the developers in order to illustrate that Pokemon are living, changing creatures. Pokemon who had migrated to the Alola region would therefore follow a different evolutionary path than their original counterparts, similar to the way real animal species in the Galapagos Islands followed their own unique evolutionary paths.

In order to create these Alolan forms, the developers revisited the Pokemon that originally appeared in Pokemon Red & Blue, since they are widely recognized by long time fans and would best express this concept with them. It would also help commemorate the 20th anniversary of the Pokémon series as a special surprise for fans.