Deoxys is not known to evolve into or from any other Pokémon, but it has four different forms. In Generation III, its form depends on what game is being played. In Generation IV, its form can be changed at will in Veilstone City or on Route 3.
Deoxys is the last Pokémon in the Hoenn Pokédex and National Pokédex within Generation III.
Deoxys mostly has the ability to change its appearance to suit whatever situation it may be in during battle.
Deoxys can release aurora every time it changes its forme.
In the anime and manga, Deoxys is also seen with the ability to create clones of itself. They appear with lifeless eyes and have dulled-down colors, and appear to be unable to use other formes besides Normal Forme.
Deoxys tend to keep to themselves, but befriend humans they trust.
Deoxys was a virus resting in a stray meteor, and while it flew through the atmosphere, the virus mutated into the first known Deoxys.