Casey's Beedrill: Given to Casey after receiving it from Ash Ketchum in The Bug Stops Here.Casey's Meganium (received as a Chikorita First partner Pokémon): Given to Casey after receiving it from Professor Elm prior to The Double Trouble Header.It was revealed in Heart of Fire! Heart of Stone!. Brock's Comfey: Given to Brock after receiving it from Nurse Joy in Alola, Alola!.Brock's Chansey (received as an Egg): Given to Brock after winning from a Pokémon Dress-Up Contest in All Dressed up with Somewhere to Go!.However it was return in Beauty and the Breeder. Suzie's Vulpix: Given to Brock after receiving it from Suzie in Pokémon Fashion Flash.Brock's Steelix (received as an Onix): Given to Brock after receiving it from Flint Prior to Showdown in Pewter City.Gary's Blastoise (received as a Squirtle First partner Pokémon): Given to Gary Oak after receiving it from Professor Oak in Pokémon - I Choose You!.Ash's Greninja (received as Froakie): Given to Ash Ketchum after receiving it from Professor Sycamore in Lumiose City Pursuit!.Ash's Scraggy: Given to Ash Ketchum after receiving it from Karena in Here Comes the Trubbish Squad!.Ash's Oshawott: Given to Ash Ketchum after receiving it from Professor Juniper in A Sandile Gusher of Change!.Ash's Donphan (received as an Egg): Given to Ash Ketchum after receiving it from an Old couple in Extreme Pokémon!.Ash's Pikachu (First partner Pokémon): Given to Ash Ketchum after receiving it from Professor Oak in Pokémon - I Choose You!.Mew (via Mystery Gift with Poké Ball Plus).

Meowth (Gigantamax via Mystery Gift with internet).Eevee (Gigantamax if the player has save data of Pokémon: Let's Go, Eevee!).

Pikachu ( Gigantamax if the player has save data of Pokémon: Let's Go, Pikachu!).

Mew (via Mystery Gift with Poké Ball Plus).

Partner Eevee ( Let's Go, Eevee! First partner Pokémon).

Partner Pikachu ( Let's Go, Pikachu! First partner Pokémon).

Generation IV Diamond, Pearl, and Platinum Generation III Ruby, Sapphire, and Emerald

Pikachu ( Yellow First partner Pokémon).

Gift Pokémon given in the games Generation I

1.7.3 Let's Go, Pikachu! and Let's Go, Eevee!.

Pokemon sun and moon free porygon