Deoxys is a Psychic type legendary pokemon from space. how it was created is when an astroid from outer space came to Earth with some space DNA virus held in the astroid which was later assumed to be the Legendary Pokemon known as Deoxys.
To find it you need to have a Solrock and Lunatone in your party and go to Mysterious Grotto. There you can find a man with a ladder in front of him. Walk up the ladder and walk over a stone bridge and when you get to the patch of grass with Pichu in it then you can start hunting for Deoxys. This will lead you to get the legendary Deoxys. It is however really rare to find.
Credit for the information: Roblox Username: Uopex
Also Creator of Deoxys in Game Project Pokemon.
Normal Form - This is Deoxys' standard form.
Attack Form - In this form, Deoxys' Attack and Special Attack rise while its defense and special defense fall.
Defence Form - In this form, Deoxys' Defense and Special Defense rise while its speed, Attack and Special Attack fall.
Speed Form - In this form, Deoxys' stats are balanced, in exchange it's Attack and Special Attack are lowered greatly.