Mew contains all the DNA of all Pokemon because Mew is their ancestor. Including Arceus. But at some point, Arceus traveled back in time and created Pokemon, including Mew, probably starting with Mew. Other Pokemon that descended from Mew could have been teleported through time and have existed first.
Mew: Mew is the youngest child of Arceus, and his most favored child. Usually, Arceus will allow Mew to get away with anything he wants, simply because Mew is the prodigy of the family.
They suggest that since Arceus is a God, they were the first. However, Arceus' first successful attempt at creating a living creature was Mew, also making Mew, in a way, the first.
Mew was created by Arceus. Arceus is the first Pokémon. All Pokémon are made in Arceus's image. Mew may have been the first (doubtedly) Pokémon on Earth, but Arceus was the first being in existence in that universe.
Arceus created Mew, who created Celebi (and many, many other Pokémon). Celebi, being the time-travel Pokémon, took Mew back in time to before Arceus existed, in order to create Arceus' egg. Remember, Mew has the DNA of all Pokémon, including Arceus.
Because it can use all kinds of moves, many scientists believe Mew to be the ancestor of Pokémon. Its DNA is said to contain the genetic codes of all Pokémon, so it can use all kinds of techniques. Mew is said to possess the genetic composition of all Pokémon.
In-game stats and moves: Arceus wins
All of Arceus' stats measure in at 120 points in every category for a total stat allotment of 720 points. Meanwhile, Mew has a stat spread of 100 points in each category, making its maximum point total 600. This gives Arceus the stat advantage.
This way, Arceus can still be a creator and Mew can still be an ancestor. One wild theory is that Arceus and Mew created each other, so they are both the first yet not the first. This is possible because Arceus predates Dialga; before Dialga, time had no concrete definition and might not have even been a linear path.
Its DNA combines the genetic composition of all existing Pokémon species; the game states that scientists within the game view it as being the single ancestor of all other Pokémon. It is shy and rarely seen by humans.
After all, Mewtwo is referred to as the first successful clone of Mew, not the only clone. Mew and Ditto have far more in common than just the ability to use Transform.
Arceus is, without a doubt, the most powerful Legendary Pokémon. This Normal type Mythical Pokémon is the creator of the universe and thus the closest that the Pokémon world has to a god. When it hatched from its egg, Arceus brought with it time, space, and antimatter in the form of the Creation Trio.
Mew is said to hold the DNA of every single Pokemon within itself. Because of that, Mew is definitely one of the most powerful mythic Pokemon in the entire series.
Ash, Dawn, Brock, and Sheena are transported to the present, only to discover that Arceus is still furious and has defeated Dialga, Palkia, and Giratina. Arceus spots Ash and recognizes him due to history's alterations, and reverses the destruction he caused and heals his former adversaries.
Arceus is thought to have created Sinnoh and Ransei, and possibly the entire Pokémon universe, along with the lake guardians, Uxie, Azelf, and Mesprit, as well as Dialga, Palkia, and Giratina (referred to as the creation trio by fans).
Like the Maltheistic portrayal of God, Arceus in some versions have been shown as a tyrannical deity who wants to destroy humanity. Arceus' actual degree of omnipotence is questionable, since in many Eastern religions the creator deity creates the world (sometimes by accident), but does not rule it.
Mew was an extremely rare Pokémon in its original games Pokémon Red and Blue. It could only be obtained through glitches in the game's programming. Mew was originally a joke between the developers at Game Freak, and was not meant to be in the final copy of the game.
Mew wasn't supposed to be there
The cartridge was really full and there wasn't room for much more on there,” Morimoto revealed. It was only because the debug features weren't included in the final version of the game, that Mew could fit in.
We do know that Mew is not a one of a kind Pokémon since scientists have used a Mew fossil for their experiments.
The first Pokemon god, Arceus, hatched from this egg and created all life.
Evolutions. This Pokémon does not evolve.
Though traditionally depicted as the god of death and the afterlife, Giratina is occasionally depicted as the god of war, famine, sickness, natural disasters, and severe misfortune, as these are often causes of death to many.
Cosmog stands out among other Legendary Pokémon as it's the first one that has the ability to evolve. After some time, Lillie's Cosmog evolves into Cosmoem and eventually into either Solgaleo or Lunala, depending on which version of the game you're playing, and this new Pokémon joins your team.
Several Pokémon are more powerful than Arceus going by overall stats. At the top of the list are Mega Rayquaza and both forms of Mega Mewtwo…
The first Pokémon ever designed
It may be entry #112 in the Pokédex, but according to Ken Sugimori – the primary designer for the Pokémon games – Rhydon was the first Pokémon ever created.