Lore of Yore!
According to Sinnoh Folk Story 3 in the Canalave Library, this kind of marriage used to be quite normal.
People x Pokémon Marriage
"In the distant past, it was somewhat stronger than the horribly weak descendants that exist today." - Pokémon Red & Blue
Magikarp
Nincada->Shedinja
Evolve Nincada into Ninjask with an empty slot in the party/and an extra pokeball in your bag
In Pokémon Contests, moves can be one of these 5 types.
Cool, Clever, Tough, Cute, Beautiful
The only move in Pokémon Colosseum and Pokémon XD: Gale of Darkness to not be a Shadow Move that has "shadow" in its name.
Shadow Ball
On February 6th, this pokémon was born.
Mewtwo
"A fur fashionsta" - Detective Pikachu (Introduced in Gen VI)
Furfrou
Inkay->Malamar
Turn the 3DS/Switch upside down when levelled up
The best part of Pokémon-Amie.
Petting your pokémon ^^
These are the 3 Teams in Pokémon GO, themed after the Legendary Birds.
Valour, Instinct, and Mystic
Raikou, Entei, and Suicune are said to represent these 3 parts of the disaster they were revived from.
The lightning which struck the tower, the flames that burned it down, and the rain which quenched the flames.
"It has an aggressive nature. It stabs prey with its long, narrow mouth to drain the prey's fluids." Pokémon Diamond (introduced in Gen III)
Beautifly
Feebas->Milotic
Beauty Stat 170+/Trade while holding a Prism Scale
Pokémon Ultra Sun and Ultra Moon may not have HMs, but they do have this minigame.
Mantine Surf.
According to Bulbapedia, this WiiWare Pokémon title in which you can play with your pokémon on a farm "is not considered a game, but rather an accessory for owners of Pokémon Diamond, Pearl, and Platinum.".
My Pokémon Ranch
Before modern pokéballs were invented, these were used by trainers to capture pokémon.
Apricorns/Apricorn Balls
"It tugs on the hands of children to steal them away. However, it gets pulled around instead. " - Pokémon Pearl
Drifloon
Mantyke->Mantine
Level up with Remoraid in the party
Despite these physically appearing in Pokémon Let's Go Pikachu & Eevee, the player is unnable to play their associated minigame as one could in Generation I and II.
Slots/Slot Machines
In Pokémon Battle Revolution, this one of the following is dependant on the player's selected gender:
-The order you challenge the colosseums in
-The difficulty (before beating the main game)
-Your starter pokémon
Your starter pokémon
This is N's full name.
Natural Harmonia Gropius
"These Pokémon line the beaches. The sticky mucous that covers their bodies can be used to soothe sunburned skin. How convenient! " - Pokémon Moon
Pyukumuku
Wurmple->Cascoon
Level 7+ if the last 2 bytes of its personality value divided by 10 has a remainder greater than or equal to 5
Flame Body, Magma Armor, and Steam Engine all have different effects in battle, but share this same effect outside of battle.
Halve the number of cycles/steps needed to hatch eggs
Pokémon Play It! is a 1999 CD ROM game which replicates another Pokémon spin-off game, and it was not the fist! A Game Boy Colour game sharing the name of this already existing spin-off was released over a year prior on December 18, 1998.
The Pokémon Trading Card Game