Raikou is a quadruped, yellow feline Pokémon with black stripes on its body. Its iris is red in color with a black pupil. It has a purple mane on its back, with white fur around its face. It has a thin, light blue colored tail with a spark shaped figure at its tip. It has a black forehead plate, with a light blue muzzle in the shape of an 'X'. It has three claws on each of its feet.
It has the Pressure ability which decreases the target's PP if they use that move on Raikou. It can also have Volt Absorb as its other ability if obtained from the Dream World.
Raikou is a Sabretooth Tiger-like creature. It carries rain clouds on its back which let it fire Thunderbolts at will. In the Pokédex, it states that it "descends with the lightning", and it "races across the land barking a cry that sounds like crashing thunder". While running, it stores up static electricity, then shoots off the excess. It is also said to help other Electric Pokémon if they are in danger.
In Pokémon FireRed and LeafGreen, Raikou roams around Kanto if the player character's Starter Pokémon was Squirtle and they have beaten the Elite Four. In FireRed and LeafGreen, it is very hard to catch because it will flee unless your Pokémon out has the ability Shadow Tag. It appears at Level 50.
In Pokémon HeartGold and SoulSilver, the player could get a Shiny Raikou at Gamestop on January 31 through February 6, 2011, which later was given out via Wi-Fi in late February 2011. You can also get it at Kanto Route 25, then the Burned Tower. It appears at Level 40 at both Route 25 and the Burned Tower.