What was first Mew or Arceus?

What was first Mew or Arceus? The entries for both Mew and Arceus purport them to be the first, with Mew being “the ancestor of all Pokemon”, and Arceus as “the creator of all Pokemon.” While this has stumped players since Arceus was introduced in Generation 4, PokeDex entries are known for being unreliable.

The entries for both Mew and Arceus purport them to be the first, with Mew being “the ancestor of all Pokemon”, and Arceus as “the creator of all Pokemon.” While this has stumped players since Arceus was introduced in Generation 4, PokeDex entries are known for being unreliable.