Pokémon #493 in the National Pokédex, a Normal-type Mythical Pokémon. It can change type when it is holding a Plate.
The last Pokémon of the fourth generation, Arceus is known as "The Original One," as it is said that it created the Pokémon universe. In particular, it's been attributed to these Pokémon:
Japanese Name: Arceus
Prior Pokémon: Shaymin
Next Pokémon: Victini
This tag implicates mythical_pokemon and gen_4_pokemon (learn more).