Suicune is an elegant, slim, blue 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. Strangely, these tails are never seen flowing behind Suicune, a possible effect from the Northern wind blowing from behind it. It has a hexagonal, aquamarine-colored crest on its forehead, red irises, a protrusion on the underside of its chin and small paws. Its paws have a small white oval on their underside.
Ryan's Suicune was once a wild Pokémon that roamed the Johto region. After Ryan discovered it, Raikou, and Entei in Ecruteak City, he began to encounter it every so often as his journey progressed. Once he entered Kanto, Suicune again appeared to him on Route 25, where he finally did battle with it; managing to catch it at the last moment. Suicune would not remain in its Pokéball, so Ryan allowed it to roam with him wherever he traveled. Once the two started trusting one another, Suicune even began allowing Ryan to ride on its back. That was the beginning of their friendship, which soon blossomed into a deep trust for the other to the point where Suicune became Ryan's favorite and always remained in his team, even after he became a Gym Leader in Hora.
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, making it the only non-Flying-type Pokémon to do so). Suicune, like the other Legendary Beasts, is also extremely fast; interestingly enough, however, it does not learn ExtremeSpeed naturally. It also sports limited mental powers.
Ryan's Suicune can communicate with him via telepathy. As noted in Pokémon Crystal, Suicune is said to be the closest of the Legendary Beasts to Ho-Oh. It is also said to have a link to the Unown.
Suicune's Pressure increases the foe's move usage by one for every successful hit. This ability works even if the Pokémon is immune to the attack's type, for example, using Earthquake against a Flying-type Pokémon.
Pressure also affects ally Pokémon in a double battle when using moves such as Earthquake, Surf, Lava Plume, Discharge or any other move which affect all Pokémon engaged in battle.
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. It's sometimes seen roaring off sides of cliffs.