Arceus is a Normal-type Mythical Pokemon introduced in Generation IV.
While it is not known to evolve into or from any other Pokemon, Arceus' Multitype allows it to change its type and form when it is holding a Plate or type-specific Z-Crystal.
Like Darkrai and Shaymin before it, Arceus was not officially recognized by Nintendo until Feburary 14, 2009, the year of its debut movie. It was officially revealed to international audiences on August 3, 2009.
Arceus is featured in Pokemon Legends: Arceus, as the game's titular character and plays a major in its plot.
Arceus is known as the "Original One", as it said that if created Sinnoh and Ransei, and possibly the entire Pokemon universe, along with the lake guardians, Uxie, Azelf, and Mesprit, as well as the Pokemon of Myth: Dialga, Palkia, and Giratina. In the past, it was worshiped by the Celestica people under the name "almighty Sinnoh".
King Arceus debuted in Arceus and the Jewel of of Life. It was angry at the people of Michina Town for Damos' unwitting betrayal of it in ancient times, and so it attempted to destroy the world. When Ash (Yuri Lowenthal/Rica Matsumoto), his friends, and Sheena were teleported by Dialga to ancient times, they directly influenced the event, changing the future for the better so that King Arceus will stop its destruction.
Arceus appeared in Hoopa and the Clash of Ages. Following the devastating incident at Dahara City, Ash, his friends, Baraz, Meray, and Hoopa saw it floating in the sky before it soared away.
Arceus appeared in Pokemon: The Arceus Chronicles, where it and the lake guardians assisted Ash and his friends in stopping a rampaging Heatran that had engulfed the Flame Plate acquired by Team Galactic with its Flash Fire Ability.
Arceus made its animated series debut as a silhouette in Showdown at the Gates of Warp!. It was called upon by Ash, his friends, their alternate world counterparts, and the people in both of their worlds to help stop Dialga and Palkia's fight and destroy the Red Chain that was forcing them to battle.
In the Legacy of Chris Thorndyke,
And he is voiced by Corey Burton in the English dub and reprised by Akihiro Miwa in the Japanese dub.