Arceus is genderless, but it can be assumed that it is male.
According to legend, Arceus is thought to have created the Sinnoh region and possibly the entire Pokémon world, the lake guardians: Uxie, Azelf, Mesprit, and the creation trio: Dialga, Palkia, and Giratina. Because of this, Arceus is thought to be one of the most long-lived of all beings.
Arceus can change its color and type using Plates.
Behavior Arceus does not suffer fools gladly, and it will attack in a violent rampage if betrayed or deceived. It also holds long grudges if angered.
Habitat Arceus lives at the Hall of Origin, which can only be accessed by use of the Azure Flute at the Spear Pillar. However, it also seems to live in a wide dimension of stars and galaxies.
Lizy: if you really are possibly the creator of the entire Pokemon world wouldn't you have the clone instead of mew and wouldn't you be in all Pokemon regions?