Disclaimer: If I owned Pokémon, there would be at least two species based on dinoflagellates. But I don't!
#326 Grumpig
The "black pearls" on its body are actually warts. They are pulled out to create jewelry for wealthy women, causing severe bleeding in the Grumpig they were taken from.
#327 Spinda
A specialist herbivore that feeds only on a species of bamboo which grows on volcanic slopes. The bamboo contains a hallucinogen that is responsible for its erratic behavior.
#328 Trapinch
It digs shallow pits in the desert, concealing its jaws beneath the sands. Those who are not careful where they step are liable to lose at least one foot before they make it out of the wilderness.
#329 Vibrava
A group of Vibrava nested under a bridge linking two cliffs over a desert. The vibrations of their wings resonated with the natural frequency of the bridge, exacerbating its instability and causing it to collapse.
#330 Flygon
During mating season, it whips up vast dust devils that sweep across the desert. Bedouins send their youths to slay them with swords to prevent these courtships from destroying their camps.
#331 Cacnea
The soil of the harsh deserts in inhabits does not contain adequate nutrients, so it must supplement its photosynthetic activity with live prey. It lays lethal spike traps.
#332 Cacturne
An intelligent, mobile cactus that stalks weary travelers through the desert. It punctures holes in itself with its spikes to create the facsimile of a friendly smile.
#333 Swablu
It pecks dirty humans violently, driven mad by anything unclean. It is raised and killed for its downy feathers, which are ideal for sweeping up dirt.
#334 Altaria
A siren of the skies that hides in dense cloud cover. Its haunting, beautiful songs lure those flying to leap off their planes and Pokémon, after which the Altaria scavenges their remains.
#335 Zangoose
An enormous herpestid that has evolved to feed almost exclusively on Seviper. It cannot be poisoned because its unique lymphatic system allows it to violently vomit up any toxins in its body.
#336 Seviper
The largest venomous snake in the world, and surprisingly one of the most agile. It has been proven to deliver enough poison to kill a Wailord when it sinks its fangs into flesh.
#337 Lunatone
A monstrous wolf stalked a town for several days before a Machamp bounty hunter tore off its forelegs. Villagers followed the trail of blood to find an eccentric Lunatone Trainer without arms.
#338 Solrock
It was worshiped with human sacrifice in ancient Mesoamerica. If it absorbs enough solar energy, it will ascend into the sky and never return.
#339 Barboach
While its flesh is rubbery, it is sometimes the only source of food for poor fisherfolk. If caught, it sends out electrical signals to its comrades to drag the fisherman into the river.
#340 Whiscash
A gigantic Whiscash sleeps in an aquifer underneath the desert in Hoenn. When it last stirred, the tremors it created were powerful enough to level half of Lilycove, to say nothing of the destruction wreaked on nearby Mauville.
#341 Corphish
An invasive species that has decimated Hoenn's native ecosytems, even driving once-common riparian species like Salava to extinction. It is dropped live into gumbos in its native land.
#342 Crawdaunt
An aggressive Pokémon popular in aquariums for its active behavior. Once an individual escaped the aquarium in Slateport and killed everyone inside before it was subdued.
#343 Baltoy
It skates over any surface smoothly using expert spins. It traces patterns until they bore into the ground, creating runic characters that induce fearful feelings in humans who view them.
#344 Claydol
It can communicate telepathically with its Trainer, but speaks only in a dead language. When it comes near an object from more than three centuries ago, its patterns glow eerily and it generates psychic impulses.
#345 Lileep
Its sticky tube feet grab prey and stuff it into its esophagus. Once a colony has completely covered an area of seabed, some detach themselves and drift to a new location to dominate it until no other life remains.
#346 Cradily
A living fossil crinoid unchanged since the Triassic. It lurks on the dark seafloor, snatching scuba divers with its jaw-like stalk.
#347 Anorith
After cloning technology advanced enough to revive this Cambrian predator, it became a popular pet. Children who pour packets of their cryptobiotic eggs into an aquarium are often unprepared for the aggressive menaces that hatch.
#348 Armaldo
A huge anomalocaridid, the top predator of the primordial sea. Its circular mouth allowed it to rip off shells and rend the exposed creatures with its awesome claws- zookeepers are understandably thrilled about its resurrection.
#349 Feebas
Its well-developed osmoregulation system contains an organ that stores pollutants away from the rest of its body, allowing it to colonize the most toxic bodies of water. If it is not prepared carefully, its flesh is very dangerous.
#350 Milotic
It exudes a calming aura. Those who swim in its deep lake feel their resistance give away and slowly sink to the bottom, where it feeds on their drowned corpses.