Regional Variant

A Regional Variant (Japanese リージョンフォーム Region Form) is a species of Pokémon found in a specific region that takes on a different form than it does in most other regions. These Pokémon have uniquely adapted to habitats that are different than those where its species naturally live in other parts of the world, such as a Fire-Type adapting to harsh cold or a prey Pokémon adapting to counter predation. This typically results in physical changes which may be either subtle or drastic in comparison to its cousins in other regions. This is similar to real-world evolution and genetic drift.

A Pokémon will always breed offspring of and evolve into its Regional Variant if it is in the corresponding region. A Pokémon will be able to breed offspring of its own form if it is holding an Everstone, regardless of region.

Currently, the regions known to produce Regional Variants are Alola and Altaris. Though not quite as drastic as these two regions, the Orange Archipelago has been observed to produce slight variations of native Pokémon.

Alola

The majority of Alolan Regional Variants have adapted simply to new surroundings, predators, and climates. These changes are purely ecological in nature, with some human interference contributing to the genetic drift.

Alolan Regional Variants
Pokémon	Sprite	Type	Ability		Sprite	Type	Ability	Evolutionary Reason
Rattata		Normal	Run Away Guts Hustle			Dark Normal	Gluttony Hustle Thick Fat	Became nocturnal to avoid predatory Yungoos.
Raticate		Normal	Run Away Guts Hustle			Dark Normal	Gluttony Hustle Thick Fat	Became nocturnal to avoid predatory Yungoos.
Raichu		Electric	Static Lightning Rod			Electric Psychic	Surge Surfer	Unknown. Thought to have eaten too many pancakes.
Sandshrew		Ground	Sand Veil Sand Rush			Ice Steel	Snow Cloak Slush Rush	Adaptation to cold climates.
Sandslash		Ground	Sand Veil Sand Rush			Ice Steel	Snow Cloak Slush Rush	Adaptation to cold climates.
Vulpix		Fire	Flash Fire Drought			Ice	Snow Cloak Snow Warning	Adaptation to cold climates.
Ninetales		Fire	Flash Fire Drought			Ice Fairy	Snow Cloak Snow Warning	Adaptation to cold climates.
Diglett		Ground	Sand Veil Arena Trap Sand Force			Ground Steel	Sand Veil Tangling Hair Sand Force	Adaptation to volcanic activity.
Dugtrio		Ground	Sand Veil Arena Trap Sand Force			Ground Steel	Sand Veil Tangling Hair Sand Force	Adaptation to volcanic activity.
Meowth		Normal	Pickup Technician Unnerve			Dark	Pickup Technician Rattled	Selective breeding by humans.
Persian		Normal	Limber Technician Unnerve			Dark	Fur Coat Technician Rattled	Selective breeding by humans.
Geodude		Rock Ground	Rock Head Sturdy Sand Veil			Rock Electric	Magnet Pull Sturdy Galvanize	Composed of magnetic rock.
Graveler		Rock Ground	Rock Head Sturdy Sand Veil			Rock Electric	Magnet Pull Sturdy Galvanize	Composed of magnetic rock.
Golem		Rock Ground	Rock Head Sturdy Sand Veil			Rock Electric	Magnet Pull Sturdy Galvanize	Composed of magnetic rock.
Grimer		Poison	Stench Sticky Hold Poison Touch			Poison Dark	Poison Touch Gluttony Power of Alchemy	Higher concentration of toxins from trash.
Muk		Poison	Stench Sticky Hold Poison Touch			Poison Dark	Poison Touch Gluttony Power of Alchemy	Higher concentration of toxins from trash.
Exeggutor		Grass Psychic	Chlorophyll Harvest			Grass Dragon	Frisk Harvest	More sunlight. Original form of Exeggutor.
Marowak		Ground	Rock Head Lightning Rod Battle Armor			Fire Ghost	Cursed Body Lightning Rod Rock Head	Adaptation to abundance of natural predators.

Altaris

The genetic drift in Altaris is most notably caused by a much harsher environment. Most Regional Variants have evolved to combat aggressive predators and elusive prey, with a few species actively being driven near extinction by humans wishing to limit civilian casualties. Aside from these trophic adaptations, many Pokémon adapted to the much different climate of Altaris, or never had to adapt to other environments than what is found in this region.

Altaran Regional Variants
Pokémon	Sprite	Type	Ability		Sprite	Type	Ability	Evolutionary Reason
Charmander		Fire	Blaze Super Luck Solar Power			Fire Dragon	Smolder Burnout	Adaptation to rival predators
Charmeleon		Fire	Blaze Super Luck Solar Power			Fire Dragon	Smolder Burnout	Adaptation to rival predators
Charizard		Fire Flying	Blaze Super Luck Solar Power			Fire Dragon	Smolder Burnout	Adaptation to rival predators
Butterfree		Bug Flying	Compound Eyes Tinted Lens			Bug Fairy	Filter Compound Eyes Pixilate	Adaptation to predators
Beedrill		Bug Poison	Swarm Sniper			Bug Ground	Hyper Cutter Swarm Long Reach	Specialization for certain prey
Pidgey		Normal Flying	Keen Eye Tangled Feet Big Pecks			Ice Flying	Keen Eye Piscivore Refrigerate	More coastal environment
Pidgeotto		Normal Flying	Keen Eye Tangled Feet Big Pecks			Ice Flying	Keen Eye Piscivore Refrigerate	More coastal environment
Pidgeot		Normal Flying	Keen Eye Tangled Feet Big Pecks			Ice Flying	Keen Eye Piscivore Refrigerate	More coastal environment
Venonat
Venomoth
Mankey
Primeape
Growlithe
Arcanine
Doduo
Dodrio
Kingler
Magikarp
Gyarados
Snorlax
Spinarak
Ariados
Dunsparce
Shuckle
Slugma
Magcargo
Aron
Lairon
Aggron
Electrike
Manectric
Tropius
Piplup
Prinplup
Empoleon
Luxio
Luxray
Shellos
Gastrodon
Gible
Gabite
Garchomp
Snivy
Servine
Serperior
Purrloin
Liepard
Sandile
Krokorok
Krookodile
Druddigon