Category 1
In Generation 1 there is a glitched Pokemon you can encounter known as "MissingClone". Popular fan theories assume that this Pokemon could have been an evolution of Marowak into Kanghaskhan, or an evolution for MewTwo.
The Pokemon is not "MissingClone" but is instead "MissingNo", which is why fan theories say it was the missing number.
In Generation 6 (Sun and Moon) we finally got regional forms. The introduction of Alolan forms made changes to many Generation 1 Pokemon, from changes in typings and stats, to general changes in appearance as well. Pokemon lore explains these changes based off the adaption to different predators, tropical environment, and prey.
Generation 6 is not Alola, Generation 7 is Alola, Generation 6 is Kalos.
Generation 8 introduced us to Morpeko, an electric and dark type with the ability Hunger Switch. Morpeko marks the first time that a "pikachu clone" has had a secondary typing.
The first "pikachu clone" to have a secondary typing is technically Marill, but the official first clone with a dual typing was Emolga.
In Generation 2, Pokemon introduced the Ghost typing, it was a small introduction with only Misdreavus making its debut, it wasn't until Generation 3 that we get multiple ghost type Pokemon.
Ghost typing was not introduced in Gen 2, it was one of the original typings in Generation 1, with the Gastly line.
Double battles are a common form of battling in the competitive seen. There are a variety of items that are helpful when double battling depending on what type of team you have, using a heat rock to extend the sunlight, a damp rock extends rain, light clay extends light screen which halves special damage and smooth clay extends reflect which halves physical damage.
Smooth clay doesn't extend reflect, light clay extends both. Smooth clay isn't an item in Pokemon.
According to lore, Grimer is made up of sludge that was exposed to lunar radiation known as X-Rays. In order to reproduce, Grimer find other Grimer that consist of different sludge and breed.
Grimer do not breed, they reproduce when pieces of sludge fall off and become new Grimers.
Two common favorite Generation 2 Pokemon are the eeveelutions Espeon and Umbreon. Eevee evolves into Espeon via high friendship during the day. It is the Daylight Pokemon, with the abilities Synchronize and Magic Bounce.
Espeon is the Sun Pokemon not the Daylight Pokemon.
Generation 8 introduced the first abilities that act as 2 abilities in one. Calyrex Shadow Rider gets the ability AS ONE (SP. ATK) which gives Unnerve (makes SP. ATK buffs of the opponent neutral) and Grim Neigh, which increases the Calyrex's SP. ATK when it knocks out an opponent. Calyrex Ice Rider gets the ability AS ONE (ATK) which gives Unnerve (makes Attack buffs of the opponent neutral) and Chilling Neigh, which increases the attack of Calyrex's Attack when it knocks out an opponent.
Unnerve doesn't neutralize either attack stat of the opponent, Unnerve makes it so that the opponent is too nervous to eat berries.
In Generation 3, the routes continue after Gens 1 (1-25), and Gen 2 (26-48). You first encounter Poochyena and Professor Birch on Route 49 and the game continues on until Route 73.
The routes in Generation 3 start at 101 and goes until route 134.
Generation 2 introduced some of our favorite parts of Pokemon games, shiny hunting. However, there are ways to hunt shiny Pokemon in Generation 1. You can attempt to look for Pokemon with the correct DVs, which when transferred to a different game can be shiny, you can also get a bugged egg from the daycare lady which can show as shiny in Generation 1.
There is no bugged egg in Generation 1, and no shiny sprites.
There are several times in the animated series where Pokemon have died (not fainted). Some have passed away such as a Stoutland in Sun and Moon, a few have been protecting trainers and towns, such as Luxray and Latios, others have also died from other instances, such as Snubbull, Pikachu and Marowak.
Pikachu hasn't actually died in the animated series, it has fainted and had its soul removed temporarily, but never actually died.
In Generation 5 we were introduced to the Pokemon Rotom, a ghost and electric type with different forms, including heat, wash, and fan. Each of these forms is an electric type with an additional typing depending on the form, however, in its debut generation all of the forms had the same electric ghost typing.
Rotom made its debut in Generation 4.
When Pokemon mega evolve, they always gain a stat equivalent to what the starting BST was, the higher the starting BST, the less stats they gain when mega evolving. Any Pokemon that starts below 500 gain 100 stats, anything less than 600 gain 80, and anything 600 or more gain only 65. Stat points can be added to any stat other than HP.
All Pokemon when they mega evolve, or primal revert gain 100 stat points total, no matter the starting BST.
Many Pokemon moves have some sort of secondary effect, although not all moves have a 100% chance of doing that secondary affect, some have the 100, such as Fake Out always flinching and Moonblast always lowering special attack. Most moves however have just a 30% chance of their secondary effect activating.
Moonblast has a 30% chance to lower the opponent's special attack.
Some Pokemon are gendered evolution, where only one gender can evolve into a certain Pokemon or where one gender doesn't evolve. These species include Pokemon Salandit, Combee, and Ralts. For gender exclusive evolutions the gender rate is 80/20. While Pokemon like Ralts are 50/50.
Gendered evolutions like Combee and Salandit have a 87.5% male to 12.5% female rate.
Generation 5 was the first time we saw different forms of legendaries. Using the DNA splicer you're able to combine either Reshiram or Zekrom with Kyurem to form Kyurem Black or White. These forms are stronger, and the ability to combine legendaries moved on into other generations. We also got the Therian forms of the genies, which is also applied to Enamorus.
The first time we got another form for a legendary is technically in Generation 2 with Shadow Lugia, which didn't alter stats, but did change the form.
In Generation 9 we were introduced to the first Steel/Ghost typed Pokemon in Gholdengo. Gholdengo also got a signature move in Make It Rain, which is a steel type special move with 120 base power, 100 accuracy, and lowers the users special attack by 1 stage.
Gholdengo is not the first Steel/Ghost type Pokemon we ever got, that title goes to the Honedge line from generation 6.
Many Pokemon share the same species name. For some reason there are 6 "Balloon" Pokemon. Those being Drifloon, Drifblim, Igglybuff, Jigglypuff, Wigglytuff, and Qwilfish.
Drifblim is not the Balloon Pokemon, it is in fact the Blimp Pokemon.
In Pokemon a popular game mechanic to increase your odds of finding a shiny Pokemon is fishing. You can chain for a Pokemon which increases the odds drastically especially when holding the shiny charm. The chain breaks however when you fail to reel in at the right time, or when you receive a "not even a nibble" message. In order to prevent this message have a Pokemon with either Inner Focus, Suction Cups, or Sticky Hold.
Inner Focus does not prevent the "not even a nibble" message, it only has an in battle effect, which prevents your Pokemon from being flinched or intimidated.
Generation 3 is the first time that Pokemon introduces not 1 but 2 sets of Pseudo Legendaries, a subclass of Legendaries with a BST (Base Stat Total) of 600. Those two from Hoenn are Beldum and Bagon. In Generation 5 we get our second and only other generation to have two Pseudo Legendaries, The Axew and Deino lines.
Axew line isn't actually a pseudo legendary, although it is a common misconception as a 3 stage dragon type.
In Pokemon lore the god creator is Arceus, a pure normal type who has the ability to change its typing if holding different plates. It is considered BST (Base stat total) wise to be one of the strongest Pokemon, other than mega and primal legendaries, with a total of 810 divided into 135 points in each stat.
Arceus actually has a base stat of 720, with 120 in each stat.
The average Box Art Legendary (Groudon, Zekrom, Ho-Oh), all have a BST of 650. Making them some of the strongest versions of legendaries while your average legendary has a BST around 570.
The average box art legend has a BST between 670-680.
Many Pokemon gain a new ability or abilities when they mega evolve. In Sceptile's case its normal abilities are Overgrow or Unburden. Overgrow increases the damage grass types move do when Sceptile is in red hp, and Unburden doubles the speed stat when an item is used. Mega Sceptile gains the ability Water Absorb, which when hit with a water move restores some hp.
Mega Sceptile has the ability Lightning Rod, which increases the speed stat when hit with an electric type move.
Grass/Ice is often considered the weakest typing in all of Pokemon, it has a large list of weaknesses, which include Flying, Fire, Fighting, Rock, Ice, Poison, Bug, and Steel. While only resisting Grass, Ground, Water and Electric.
Grass/Ice typing is not weak to Ice, because although Grass is weak to Ice, Ice is only resists itself, making Ice neutral.
The last time Pokemon released an eeveelution was with the release of fairy types and Sylveon in Generation 6. The reason Pokemon hasn't released a new eeveelution since then is because the community outcry about leaked designs led to Pokemon not releasing any more in any more of the generations.
Pokemon refuses to release a new eeveelution because there exists so many community designs and they're afraid of getting sued.