Suicune

Suicune is a legendary Water type Pokémon and one of the three legendary beasts, along with Entei and Raikou, created by Ho-oh after the Brass Tower was burnt down. It first appeared in Generation ll and is said to be the embodiment of the North Wind. Suicune has the unusual ability to purify dirty or contaminated water and can also walk across water.

Suicune was the version mascot for Pokémon Crystal.

Location
In Gold and Silver, Suicune can be caught roaming about Johto.

In Crystal, it can be caught in the Tin Tower when the player has the Clear Bell.

It can only be caught in Ruby and Sapphire by trading. The same goes for Emerald.

In FireRed and LeafGreen, it can be caught roaming about Kanto, after you defeat the Elite 4 if you chose Charmander as your starter pokémon.

In Super Smash Bros.
Suicune shows up in Super Smash Bros. Melee as a pokéball pokémon and is quite rare. Once released, Suicune will use Icy Wind causing a cloud of wind to surround it. Any character that touches it will get damaged and characters that are already heavily damaged may get frozen.

Suicune makes a return in Super Smash Bros. Brawl with a new attack. Suicune will use Aurora Beam when released which will send a beam of ice across the stage which strikes anyone in front of it. This attack will usually K.O anybody it hits.