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. Purely cosmetic differences such as this, as well as differing Arbok patterns and Shellos morphs, are not considered Regional Variants.

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		Bug Poison	Compound Eyes Tinted Lens Run Away			Bug Electric	Illuminate Shield Dust Motor Drive	Adaptation to predators.
Venomoth		Bug Poison	Shield Dust Tinted Lens Wonder Skin			Bug Electric	Illuminate Shield Dust Motor Drive	Adaptation to predators.
Mankey		Fighting	Vital Spirit Anger Point Defiant			Psychic Fire	Telepathy Stakeout Burnout	Hotter, more hostile environment.
Primeape		Fighting	Vital Spirit Anger Point Defiant			Psychic Fire	Telepathy Stakeout Burnout	Hotter, more hostile environment.
Growlithe		Fire	Intimidate Flash Fire Justified			Fire Water	Oilslick Intimidate Corrosion	More coastal environment.
Arcanine		Fire	Intimidate Flash Fire Justified			Fire Water	Oilslick Intimidate Corrosion	More coastal environment.
Magikarp		Water	Swift Swim Hustle			Water Dragon	Moxie Swift Swim Sheer Force	Required to adapt to hostile environment.
Gyarados		Water Flying	Intimidate Moxie			Water Dragon	Moxie Swift Swim Sheer Force	Required to adapt to hostile environment.
Spinarak		Bug Poison	Swarm Insomnia Sniper			Dark Poison	Poison Touch Shadow Tag Merciless	Specialization for nocturnal habits.
Ariados		Bug Poison	Swarm Insomnia Sniper			Dark Poison	Poison Touch Shadow Tag Merciless	Specialization for nocturnal habits.
Shuckle		Bug Rock	Sturdy Gluttony Contrary			Poison Water	Poison Touch Effect Spore Corrosion	Adaptation to deter predators.
Linoone		Normal	Pickup Gluttony Quick Feet			Flying	Precise Streamlined Aerilate	Specialization as a predator.
Electrike		Electric	Static Lightningrod Minus			Electric dark	Galvanize Berserk Speed Boost	Required higher capacity to discharge lightning.
Manectric		Electric	Static Lightningrod Minus			Electric dark	Galvanize Berserk Speed Boost	Required higher capacity to discharge lightning.
Luxio		Electric Dark	Rivalry Intimidate Guts			Electric Psychic	Intimidate Anticipation Cursed Body	Ancient branched subspecies bred by humans.
Luxray		Electric Dark	Rivalry Intimidate Guts			Electric Psychic	Intimidate Anticipation Cursed Body	Ancient branched subspecies bred by humans.
Shellos		Water	Sticky Hold Storm Drain Sand Force			Water Poison	Sticky Hold Stench Poison Touch	Adaptation to deter predators.
Gastrodon		Water Ground	Sticky Hold Storm Drain Sand Force			Water Poison	Sticky Hold Stench Poison Touch	Adaptation to deter predators.
Gible		Dragon Ground	Sand Veil Rough Skin			Dragon Water	Rough Skin Swift Swim Pressure	Original, aquatic form that never had to adapt to land.
Gabite		Dragon Ground	Sand Veil Rough Skin			Dragon Water	Rough Skin Swift Swim Pressure	Original, aquatic form that never had to adapt to land.
Garchomp		Dragon Ground	Sand Veil Rough Skin			Dragon Water	Rough Skin Swift Swim Pressure	Original, aquatic form that never had to adapt to land.
Snivy		Grass	Overgrow Infiltrator Contrary			Grass Poison	Overgrow Chlorophyll Contrary	Mimicking Ekans to deter predation.
Servine		Grass	Overgrow Infiltrator Contrary			Grass Poison	Overgrow Chlorophyll Contrary	Mimicking Ekans to deter predation.
Serperior		Grass	Overgrow Infiltrator Contrary			Grass Poison	Overgrow Chlorophyll Contrary	Mimicking Arbok to intimidate rivals.
Sandile		Ground Dark	Intimidate Moxie Anger Point			Water Dark	Infiltrator Water Absorb Strong Jaw	Original, aquatic form that never had to adapt to land.
Krokorok		Ground Dark	Intimidate Moxie Anger Point			Water Dark	Infiltrator Water Absorb Strong Jaw	Original, aquatic form that never had to adapt to land.
Krookodile		Ground Dark	Intimidate Moxie Anger Point			Water Dark	Infiltrator Water Absorb Strong Jaw	Original, aquatic form that never had to adapt to land.
Sigilyph		Psychic/Flying	Wonder Skin Magic Guard Tinted Lens			Psychic/Grass