Gen 1
(LeafGreen) Its brain can outperform a supercomputer. Its IQ is said to be around 5,000.
Alakazam
(HeartGold) To fire its toxic spikes, it must inflate its body by drinking over 2.6 gallons of water at once.
Qwilfish
(Emerald) It alters its form depending on the weather. Changes in the climate such as the temperature and humidity appear to affect its cellular structure.
Castform
(Platinum) If it senses strong sunlight, it opens its folded petals to absorb the sun's rays with its whole body.
Cherrim
(White) This ancient bug Pokémon was altered by Team Plasma. They upgraded the cannon on its back.
Genesect
(LeafGreen) Puts enemies to sleep, then eats their dreams. Occasionally gets sick from eating only bad dreams.
Drowzee
(SoulSilver) When it needs to think, it rotates its head 180 degrees to sharpen its intellectual power.
Noctowl
(Emerald) After spending thousands of years in harsh deserts, its blood transformed into the same substances as sand. It is nocturnal, so it hunts at night.
Cacturne
(Platinum) It prefers an arid atmosphere. It leaks water that looks like tears when adjusting its moisture level.
Bonsly
(White) With the mist from its forehead, it can create shapes of things from dreams it has eaten.
(FireRed) Its whole body is composed of muscles. Even though it's the size of a human child, it can hurl 100 grown-ups.
Machop
(HeartGold) Its body can't be harmed by any sort of attack, so it is very eager to make challenges against enemies.
Tyranitar
(Emerald) It sharply senses even subtle changes in the sky and the land to predict natural disasters. It is a long-lived Pokémon that has a life-span of 100 years.
Absol
(Platinum) To protect itself, it afflicts those around it with nightmares. However, it means no harm.
Darkrai
(White) Having removed its heavy shell, it becomes very light and can fight with ninja-like movements.
Accelgor
(LeafGreen) Its tail fin billows like an elegant ballroom dress, giving it the nickname of "The Water Queen."
Goldeen
(SoulSilver) In South America, it is said that its right eye sees the future and its left eye views the past.
Xatu
(Emerald) It can't keep still because its blood boils with energy. It runs through the fields and mountains all day to calm itself. If it doesn't, it can't sleep at night.
(Platinum) It is surprisingly quick to anger. It holds its mouth agape as a display of strength.
Hippowdon
(Black) This brutal Pokémon travels the skies on its six wings. Anything that moves seems like a foe to it, triggering its attack.
Hydreigon
(LeafGreen) It can live in or out of water. When out of water, it constantly sweats to keep its body slimy.
Poliwhirl
(SoulSilver) After nesting in bramble bushes, the wings of its chicks grow hard from scratches by thorns.
Skarmory
(Ruby) [Redacted] can always been seen with a big, happy smile on its face. Look at its tail to determine if it is angry. When angered, this Pokémon will be slapping the ground with its tail.
Wynaut
(Platinum) Evolution made it even more devious. It communicates by clawing signs in boulders.
Weavile
(Black) With its thin, veil-like arms wrapped around the body of its opponent, it sinks to the ocean floor.
Frillish