It is not known to evolve into or from any other Pokémon.
Along with Raikou and Entei, it is one of the legendary beasts created by Ho-Oh after the burning of the Brass Tower. Of the three legendary beasts, Suicune is said to represent the rains that quenched the flames of the burning Brass Tower.
Suicune is an elegant, slim, blue mammal-like Pokémon with white diamond-shaped spots and a white underside. Suicune has a purple, cape-like mane that resembles a northern aurora (Aurora Borealis) or a flowing river and two white streamer-like tails. It has a long, white snout, and unlike Entei or Raikou, its teeth are blunt, as if those of an herbivore. It has a hexagonal, aquamarine-colored crest on its forehead that resembles the antlers of a Qilin or slightly altered female sign, red irises, a protrusion on the underside of its chin, and small paws. Its paws have a small white oval on their underside.
Suicune is a genderless species but it is referred as a male in Pokémon Adventures.
Suicune has the power to purify dirty water and can walk across water. Northern winds always seem to blow wherever it shows up. Because Suicune is the embodiment of the northern winds, it is able to learn and use almost every attack with relation to the wind (such as Gust, Icy Wind, Blizzard, and even Tailwind. Suicune, like the other Legendary Beasts, is extremely fast. It also sports limited mental powers.
In the anime, Suicune has shown a heroic, serious and calm nature to dangerous situations and has appeared just in time to save the main character or character of the day, as shown in Drifloon on the Wind! when it races to save Ash and Paige.
It's sometimes seen roaring off sides of cliffs.
Since Suicune is a member of the Legendary Beast Trio, Suicune races around the land.
This Pokémon was unavailable prior to Generation I.