1. Mewtwo
   Gengar
2. Alakazam
   Misdreavus

During the anime, Ash runs into a Gengar in the episode "The Tower of Terror." The Gengar he finds tries to entertain him by performing standup routines, but the attempts fail to amuse Ash.

1. Venusaur
   Metapod
2. Kakuna
   Nidoking

Venusaur is the top evolve form of Bulbasaur, one of the original starter Pokemon in Red and Blue. Ivysaur is the middle evolve form, giving the grass and poison type Pokemon a three set evolution.

1. Corphish
   Treecko
2. Snorunt
   Aipom

Though Treecko typically lives in captivity, it can be found making a nest in giant trees located throughout the forest. It's extremely protective of its home and will run off any predator that threatens a tree it inhabits.

1. Breloom
   Piloswine
2. Granbull
   Tyranitar

Tyranitar made its first appearance in the Pokemon movie "Celebi: The Voice of the Forest." In the movie, Tyranitar is turned dark by the Iron Masked Marauder, who uses the powerful Pokemon as he tries to capture Celebi.

1. Charmander
   Squirtle
2. Bulbasaur
   Poliwag

The Squirtle Squad first appeared in the anime as a gang of Squirtle who were bent on causing trouble for travelers. However, Ash makes friends with the leader of the squad, who agrees to join their team after an encounter with Team Rocket.

1. Blaziken
   Arcanine
2. Vulpix
   Magmar

Magmar is the strongest Pokemon used by Blaine, the Cinnabar Island Gym Leader. A master with fire type Pokemon, Blaine gives the Volcano Badge to any trainer who is good enough to defeat him.

1. Raikou
   Jolteon
2. Magnezone
   Electivire

Electivire is loaded with powerful electricity from head to toe. This electricity can be administered on foes from the tips of its tails, where it releases attacks ranging over 20,000 volts.

1. Gyarados
   Magikarp
2. Lapras
   Omastar

Gyarados is the evolve form of Magikarp, one of the weakest Pokemon in the game. However, for trainers willing to take the time to train and evolve a Magikarp, they will end up with a Pokemon capable of destroying entire cities with its rage.

1. Geodude
   Rhyhorn
2. Onix
   Cubone

Onix is a massive rock type Pokemon that is actually the tallest of its type. They can be found in caves and mountains, where it will dig tunnels underground, causing tremors that resemble an earthquake.

1. Venipede
   Semipour
2. Grotle
   Absol

Introduced in Generation III, Absol does not originally have an evolve form. However, in Generation VI, Absol is given a mega evolve form, which can only be reached by equipping an Absolite.

1. Turtwig
   Piplup
2. Chimchar
   Shinx

Like many other fire type Pokemon, Chimchar has a flame for a tail. This flame is powered by gases in its belly and can't go out even if it's raining, but Chimchar will extinguish the flame when it goes to sleep.

1. Marshtomp
   Mudkip
2. Swampert
   Torchic

On his journey through the Hoenn region, Brock obtains a Mudkip from a Pokemon breeder named Old Man Swamp. Brock befriends the Mudkip after saving it from Team Rocket during one of their many plots to steal strong Pokemon.

1. Ditto
   Pinsir
2. Snorlax
   Mr. Mime

In Pokemon Red and Blue, Snorlax can only be found sleeping on various routes, where it blocks the path to the next town. This Pokemon will awakened if you use a Poke Flute, but be careful when it wakes because it's ready to attack.

1. Donphan
   Ursaring
2. Azumarill
   Igglybuff

When in danger, Donphan curls up like a wheel and rolls around violently, smashing anything in its way. In fact, it moves around with such force in this position that it has the ability to knock down a house.

1. Tyranitar
   Gyarados
2. Dragonite
   Charizard

Charizard has always been one of the most powerful Pokemon in the franchise, utilizing both fire and dragon type moves in battle. Charizard's potential was even recognized when it was featured on the cover of one of the first Pokemon games, Pokemon Red.

1. Pulse
   Manectric
2. Minun
   Electabuzz

According to the Ruby Pokedex, Manectric struggles to contains its own electricity, as electric charges constantly spew from its mane. This electricity is so powerful that it creates thunderclouds during battle.

1. Hippopotas
   Snover
2. Mamoswine
   Rotom

Unlike hippos in real life, Hippopotas never goes near the water, as it prefers bathing in the sand instead. This sand is expelled from its body like sweat as well, protecting the ground type Pokemon from germs.

1. Exploud
   Slaking
2. Sableye
   Aggron

Slaking is a lazy Pokemon who mainly lays around and sleeps while storing energy. This laziness extends to battle, as Slaking can only attack opponents every other turn, but these attacks are extremely damaging.

1. Tauros
   Latios
2. Scyther
   Rapidash

Ash utilizes the incredible speed of a Rapidash to win the Big P Pokemon Race in the episode "The Flame Pokemon-athon!" Ash started the race on a Ponyta before it evolved into a Rapidash just before the end of the race.

1. Pikachu
   Charmander
2. Bulbasaur
   Squirtle

No Pikachu, and maybe no Pokemon, is as famous as the one that belongs to Ash Ketchum in the anime. Ash's Pikachu is not only a fan favorite, though, as it is also extremely powerful, often defeating opponents that are considered much stronger.

1. Umbreon
   Flareon
2. Jolteon
   Vaporeon

Gary, who is Ash's main rival, carries around an Umbreon as one of his prized Pokemon. He raised the Umbreon from the time it was an Eevee, evolving it sometime between his journey from the Kanto region to the Johto region.

1. Plusle
   Minun
2. Victini
   Sandshrew

Victini has been gifted with many unique attributes like invisibility and the ability to learn Searing Shot, a move no other Pokemon can learn. However, one of its greatest attributes is that it can share part of its infinite amount of energy with other people simply by touching them.

1. Magcargo
   Slugma
2. Camerupt
   Numel

When Flannery first appears in the anime, she carries around two Slugma named Meg and Mag. Mag, however, evolves into a Magcargo after an encounter with Team Rocket, who tried to steal another Pokemon Flannery had, Torkoal.

1. Jigglypuff
   Clefairy
2. Clefable
   Mr. Mime

Jigglypuff has a pair of eyes that will easily mesmerize anyone who crosses its path. However, once Jigglypuff captures your attention, it sings a melody that will put anyone to sleep.

1. Azelf
   Arceus
2. Giratina
   Empoleon

Giratina made its first appearance in the Pokemon movie titled "Giratina and the Sky Warrior." In the movie, the Reverse World is introduced as a new universe and as the home of Giratina.

1. Celebi
   Lugia
2. Ho-Oh
   Zaptos

Since the beginning of the anime, Ho-Oh has been an inspiration for Ash as he journeys across the Pokemon world. It even helped Ash get over his loss in the Silver Conference when he set his sights on his next adventure in the Hoenn region.

1. Anorith
   Ekans
2. Arbok
   Seviper

Seviper has a poisonous bite that can be lethal against opponents in a battle. The bite is commonly used to defend against encounters with Zangoose, a Pokemon that it has been feuding with for generations.

1. Cyndaquil
   Chikorita
2. Totodile
   Torchic

Like other starter Pokemon, Totodile is the first of three evolutions, with the others being Croconaw and Feraligatr. However, Totodile has a unique evolution pattern, as it evolves at level 18 and again at level 30.

1. Kadabra
   Hypno
2. Drowzee
   Alakazam

If you watch horror movies, you know just how creepy Freddy Krueger can be when he infiltrates your dreams, but Hypno might just rival the nightmare serial killer. Hypno won't kill you, though, but instead, it will just feed on your dreams.

1. Primeape
   Poliwrath
2. Machamp
   Golem

An encounter with Primeape always ends up being more than one could ask for. If you need evidence, look no further than the episode "Primeape Goes Bananas," where a Mankey steals Ash's hat before evolving into a Primeape, causing even more trouble.

1. Machoke
   Machop
2. Machamp
   Hitmonlee

Machamp is characterized by its four powerful arms, which are said to be strong enough to lift mountains. These arms provide it with plenty of techniques during a fight, as it throws ceaseless punches and chops.

1. Abra
   Lugia
2. Deoxys
   Mewtwo

After being born from Mew, Mewtwo was captured and used in a science experiment involving gene splicing. This experiment gave Mewtwo immense power, but it also made it very cruel to both humans and Pokemon.

1. Suicune
   Entei
2. Raikou
   Arcanine

After the burning of the Brass Tower, Entei was resurrected by Ho-Oh along with Raikou and Suicune. A fire type Pokemon, Entei is believed to cause the eruption of volcanoes anytime it barks.

1. Whismur
   Exploud
2. Breloom
   Lombre

Exploud has tubes that cover its body, which it uses to pull in air before launching a vocal attack. When it does launch one of these bellowing moves, they are so loud that earthquakes result.

1. Hitmontop
   Hitmonlee
2. Hitmonchan
   Tyrogue

Hitmontop spins at such high speeds that it moves faster while spinning than it does walking. If the Pokemon remains in one place while spinning, it will drill a hole into the ground.

1. Greninja
   Noivern
2. Slyveon
   Xerneas

Xerneas can change the way it looks by shifting between Active Mode and Neutral Mode. Despite its mode, the body of the Pokemon remains black, and it keeps its tail along with a blue stripe down its back.

1. Kingdra
   Bagon
2. Dragonite
   Salamence

Though it lacks an athletic build, Dragonite is one of the fastest Pokemon when it takes to the sky. This dragon type is actually so fast in the air that it travels faster than the speed of sound.

1. Tyranitar
   Aipom
2. Magneton
   Metagross

Metagross is a unique type combination of steel and psychic. Its psychic powers are fueled by its four brains, which come together when two Metangs fuse, giving it a brain as powerful as a supercomputer.

1. Groudon
   Moltres
2. Lugia
   Kyogre

Groudon is one of two Pokemon capable of Primal Reversion, which was introduced in Pokemon Omega Ruby and Alpha Sapphire. This transformation gives a Pokemon the ability to harness the energy of nature to unleash its true powers.

1. Timburr
   Gurdurr
2. Conkeldurr
   Crustle

Evident by the pillars it carries, Conkeldurr has the ability to create concrete. The Pokemon taught this ability to humans over 2,000 years ago and can even be found helping workers around construction sites like in the episode "Genesect and the Legend Awakened."