In the Sinnoh mythilogy , it's said that Arceus is the first pok?mon , preceding the humans and all other kinds of pokemons . But Rhydon is said to be the first ever designed pokemon by GF , so it's possible . And Bulbasaur is the first entry of the Pokedex , so these three answers are all corect , depending on details . But i really don't know why they have put Mew as an answer he's not the first pokemon , he's just the ancestor of all common - non legendary- pokemons . He have the DNA of all of the? , as stated in the Pokedex .