Disclaimer: If I owned Pokémon, May-December Couple and Sci-Fi Maniac would be Trainer classes in every game. But I don't!
#426 Drifblim
Studies of Drifblim allowed scientists to determine the direct relationship between the temperature and volume of gases. The particular gas in its body is composed of dead souls.
#427 Buneary
It plays dead to avoid predators. This behavior backfires when parents find one in the backyard, believe it to be a stuffed animal and throw it in the washing machine.
#428 Lopunny
It hides in the shadows, where its silhouette appears to be that of a woman. When men approach, it subdues them with powerful kicks.
#429 Mismagius
It may communicate telepathically with its Trainer, but always speaks backwards. If a mother hears its cry, her baby will be stillborn.
#430 Honchkrow
To become the leader of its murder of Murkrow, it had to kill a man. Oddly, most police will never investigate a Honchkrow's crime even if ample evidence is available.
#431 Glameow
A housecat starved to weakness by its owners to produce an elegant look. As a result of the breed's narrowed birth canal, it almost always dies when giving birth.
#432 Purugly
The breed has never lost a "World's Ugliest Cat" competition. As a result, it suffers from horrifically low self-esteem and commonly commits suicide.
#433 Chingling
A loud Pokémon of misty mountain passes. It has coevolved a relationship with Mandibuzz- by chiming every time hikers fall to their deaths, the vultures will seek their carcasses rather than preying on it.
#434 Stunky
Its scent gland is removed when it is captured for the pet trade. The operation stimulates the release of testosterone, making it viciously aggressive.
#435 Skuntank
It fights with house pets, spraying them with a scent that can never be scrubbed out. As a last-ditch measure, it can set itself on fire, causing an explosion that kills it along with its attacker.
#436 Bronzor
Its body appears to fit perfectly into certain wall depressions on some temple doors, leading researchers to believe it is an animated key. It is terrified of being placed in these sunken areas, however.
#437 Bronzong
It lies dormant until it is rung. After awakening, it threatens to withhold rain unless it is given a blood sacrifice.
#438 Bonsly
They are purchased in pots. Regretful owners who vow that this time they'll remember to water their plants are in for an unfortunate surprise when they do change their behavior.
#439 Mime Jr.
It mimics objects in its surroundings to escape danger. Unfortunately for Mime Jr., it is a little too skilled at mimicking candyfloss.
#440 Happiny
While it usually carries around a rock, it is sometimes lucky enough to find a real egg. When the egg hatches, it eats the newborn creature.
#441 Chatot
It can repeat anything it has ever heard with perfect recall. Most Chatot Trainers fall prey to its skilled blackmail and become virtually enslaved by their parrot.
#442 Spiritomb
A Jirachi transformed into a twisted form as punishment for granting unforgivably evil wishes. It tempted the Buddha underneath a tree long ago.
#443 Gible
An ectotherm vulnerable to cold. It bites onto large prey and stays firmly and painfully attached until the big creature dies- often a period of days.
#444 Gabite
They run across the sand without the slightest hindrance. They attack in packs, quickly adapting complex hunting formations to take down even intelligent prey.
#445 Garchomp
It can swim through sand with ease. It preys on almost any creature that enters its desert habitat, giving little warning before striking like lightning.
#446 Munchlax
It is not a picky eater. Rotting corpses are one of its favorite treats, although it will create fresh ones if they are in short supply.
#447 Riolu
A Riolu is the mascot of a major toy corporation. The buffoonish character's mannerisms have led to real Riolu being abused and mocked.
#448 Lucario
Every person has an aura of one of fourteen or fifteen colors. Lucario kill those with black auras.
#449 Hippopotas
Its milk is pink because its circulatory system is unable to prevent its milk and blood from mixing. Children rarely notice when it is substituted for their strawberry-flavored Moomoo milk.
#450 Hippowdon
It was feared in ancient Egypt as a dark god of storms and chaos. It kills more people annually than Krookodile.