Which came first, the Arceus or the Mew? Also if anyone knows can you please tell me the correct pronounciation of Arceus' name?
Well, I believe that Arceus came first, because it created the world. Mew is the ancestor of all Pokémon, which makes it confusing, but I found an explanation. Perhaps all Pokémon known today evolved from Mew. Not the Pikachu into Raichu type of evolution, but the real life, Charles Darwin evolution. This explains why Mew is so rare. But that's just a theory I believe in. I saw it in a video, but I'm too lazy to go find it at the moment... And even though everyone says "Ar-SEE-us," the real, offical pronunciation is "Ar-KEY-us." (Sorry if I stole your thunder or whatever, Arc, I just wanted to explain a bit more.)
Rhydon I think lore wise Arceus came first and Mew was just the first creature it made, too me that seems similar to the bible creation story since Arceus is known as the god of Pokémon, so I'm just assuming the Pokémon world would have a similar lore.
Since everyone seems to agree that the chicken came first, I just want to say that it's ar-see-us. I don't give a rat's... butt about the official pronunciation, it's clearly ar-see-us. it just rolls off the tongue better. But seriously, it really doesn't matter whether you pronounce it arceus or arceus, we all know who you talkin' about anyway.