Contrary to popular belief, Pokémon games follow a very predictable path of covering certain archetypes, primary models for species for in-game and competitive metagame. The oddities occur, if any, when these archetypes are used when, or how many, as certain archetypes can be used multiple times within a generation.
We divide these archetypes to
1.Eternal archetypes: Archetypes dependent on the very existence of games.
2.Generational archetypes: Archetypes dependent on which generation is the generation people are in.
3.Miscellaneous: Archetypes that are not dependent on generations, but can appear in multiple generations.
Having around 525-535 BST, starters generally follow similar patterns, a speeder, a tank and a wall. Most recent starters have been around 528-534 BST.
They generally start around 320 and go to 405-415, though the recent ones are in 420.
Having around 410+-420+ BST, regional rodent is the regional Normal-type that appears in early and mid-game routes, as well as some end-game ones. Rodents are typically physical oriented, with the highest Sp. Atk variant being Watchog's 60. Most rodents also get Super Fang through tutor.
Having around 479-499 BST, for third stagers, and 440-455 BST for second stagers, regional birds are the Normal/Flying or x/Flying Pokémon that appear in early and mid-game routes, as well as some end-game ones. Birds are typically physically oriented, though there are some special oriented ones like Noctowl.
Having around 475-497 BST for second stagers, 485-523 for third stagers, regional electrics are the first Electric-type you get in-game. Regional electrics serve as the Electric starter of the region, with Pikachu literally being a starter in Yellow. Regional electrics tend to be regular animals, predominantly mammal.
Having around 450-475 BST, the regional fish has traditionally been a fodder for Good Rod or Super Rod in the regions that had those rods. In the ones that don't have different rods, the regional fish appears in special fishing locations, and in Basculin's case, surfing. Regional fish are generally in Water 2 Egg Group only, and tend to be pure Water or part Water. They tend to have low stats and dry movepools, save for exceptions like Sharpedo and Lanturn.
f. The Pikaclone:
Having around 405-435, each generation since Gen 3 had a Pikaclone, a single-stage copy of Pikachu's design that shares its iconic electric cheek sacs. These sacs allow them to learn Nuzzle Gen 6 onwards.They generally encountered in similar ways to Pikachu's original introduction, in common roads but appearing with low encounter rates.
g. The Mascot Legendaries:
Having around 670-680 stat, Mascot Legendaries the Legendaries described each generation's boxart Gen 2 onwards. TPCi calls them just Legendaries. The Mascot Legends Gen 2 onwards have a third member that is generally stronger than the two, that gets focus later.
h. Generational Mascot:
Traditionally called "Mew", generational mascots are 600 BST Mythical (event Legendary) Pokémon that occur first in the given Pokédex of a generation. Appearing first for generational promos, generational mascots tend to get redistributed several times in a given generation. They tend to be either feminine or baby-like.
i.Regional Early Grass:
Appearing in the early routes around after the first gym, Regional Grass is one of the primary archetypes that appeared in all generations. This archetype serves as the pseudo-starter for the Grass-type, and as such it tends to be three staged(minus Gen 5 and 6 early Grass-types) and in even generations tend to have a version counterpart that serves the same purpose(sans Gen 7).
k.Regional Early Fighting:
Regional early fighting is generally the first Fighting-type you encounter in the game. Three stage ones tend to be around 505, and second stage ones tend to be around 474-500 range(single stages, if exist tend to be around 455-465 range).
a. Mid-game Fighting-type:
Generally in even generations there is one or two mid-game Fighting-types with better stats than the early Fighting-type, or have unique type combinations or typings. They tend to be around 490-525 BST range.
Each odd generation had at least one Spore user, generally two-staged, and around 405-464 BST range. These mushroom have been part Grass and part something else. So far, Bug, Fighting, Fairy and Poison has been used.
b. The Poison Blob:
Each odd generation had at least one Sludge user(though Alolan Muk doesn't get his move, it is still associated with it). with high HP and Poison-typing. These poison blobs tend to be two staged and tend to have Black Sludge as their held item and learn Stockpile related moves. They range between 467-500 BST.
With the exception of Gen V, whose break was compensated by Gen 6, Crabhammers are generally Physically oriented, generally Water-typed Pokémon that belong to Water 3 Egg Group. Having a crustacean shape, these Pokémon tend to focus on offense at the cost of Speed and other stats.
d. Regional Psychic, Three-Staged:
Ranging 485-520 BST range, one of the regional Psychics in odd generation tend to be three staged. Some of them even have competitively viable middle stages. With the exception of Alolan Raichu, they tend to be difficult raise, but compensate with high Special Attack and/or Defense.
e.Regional Grass, Gimmicky Single Stage:
Each odd generation and some even generations like Gen 4 had a single stage Grass-types that were rare to encounter, specific to one region and had some special gimmick.
Two of them, Tangela and Roselia, have been elevated to regional grass status(regional late-game and regional early-game respectively.)
While not a true archetype of its own, each generation has so far had one end-game Ice-type, including in regions that have introduced more easily accessible Ice-types. Because this is not a true archetype, but more of a pattern, much cannot be said about it.
b. Regional genderless Mineral.
While not a true archetype, with the exception of Johto, all generations have introduced at least one evolutionary line that belonged to Mineral Egg Group and had no gender, with even generations generally having one, and odd generations having about three. These genderless Pokémon tend to be around 480 to 500 range, though most recently in the generations 6 and 7 there hasn't been any that evolves or evolved from a previous stage.
c. Honorary Pikaclone:
Though a true archetype of its own, three of the seven generations have included an evolutionary family that resembled Pikachu one way or the other, without sharing its Electric-type. These have been around 420-470 BST range, with the two of the evolving ones having evolutions that mimic Raichu's design.
Alternatively known as Fat Pink Blob(though Comfey deconstructs that image), the cleric is a rare Pokémon with generally high defensive stats that is focused on healing allies through moves like Aromatherapy, Heal Pulse,. Clerics typically do not evolve and have around 445-485 BST stats, at least in their initial introduction. Most clerics in Fairy Egg Group except Alomomola(Water1/2) and Comfey(Grass).
Alternatively known as Prehistoric Pokémon, the fossils are Rock-type Pokémon player can resurrect from a Fossil item. Having around 495-521 range, fossils tend to start from high BST positions and evolve relatively late. Unlike conventional Rock-types, they are not bound by conventional type combinations. They tend to get Ancient Power. This is listed here as not all regions have fossils due to geographical history.
Belonging to Field Egg Group, this group of animal-based Pokémon are very similar species, having access to Fighting-type and Punching moves, appearing bipedal in their forms, having stat totals of 495-505 and having Attack start between 120-130. They tend to get Hammer Arm.
g. The Cats:
Belonging to Field Egg Group, this group of animal-based Pokémon are similar species that are generaly associated with Dark and Fairy-types, and have good Speed in expense of other stats. They tend to have stats around 400-450 BST.