Pokémon #069.
Bellsprout
This was the first region to introduce Regional Forms, of certain Pokemon.
Alola
These two Legendary Pokémon are based off of the Chinese concepts of Yin and Yang.
Reshiram and Zekrom
This starter Pokémon group resembles the Chinese Zodiac creatures.
Fire Starters
In Generation 1, this move had the unique property of being the only one that could hit a Pokémon using Dig.
Earthquake
Pokémon #025.
Pikachu
This is the first region to introduce 3D Pokemon models in game.
Kalos
These are the elements Dialga, Palkia, and Giratina represent.
Time, Space, Antimatter
This Pokemon is the "villain" of Galar's Darkest Day.
Eternatus
This is the only Legendary Pokémon that can evolve.
Cosmog -> Cosmoem -> Solgaleo/Lunala
Pokémon #149.
Dragonite
These are the only two "connected" Regions.
Kanto and Johto
These are the "trio masters" for the legendary: birds, beasts, and golems.
Lugia, Ho-oh, Regigigas
This Legendary Pokémon shaped the Pokémon World.
Regigigas
This Pokémon has the highest base stat total of any non-Legendary, non-Mythical Pokémon.
Slaking - 670
Pokémon #500.
Emboar
This Region introduced The Distortion World.
Sinnoh
This is the only Mythical Pokémon that can breed.
Manaphy
This Legendary Pokémon represents Pure light itself.
This Legendary Pokémon codenamed: XD001, is a unique variant of another Legendary Pokémon.
Shadow Lugia
Pokémon #777.
Togedemaru
This Region has towns and cities name after musical terms.
Unova
This Pokemons Pokedex number is #000.
Victini
This Pokémon has a unique Pokedex entry from others of its type. This individual one is known as the War Pokémon.
AZ's Floette
This is the only Pokémon whose type combination has changed between generations without a form.
Magnemite line (Gen I: Electric → Gen II onward: Electric/Steel).