Get Pokemon emerald and then you can get all three without cheats or trading
There is no other way.
Mew three isn't a Pokemon just a fake made by a fan
It's unfortunately not possible to get all three of Sinnoh's (Pokémon Diamond, Pearl and Platinum) starter Pokémon without cheats or trades. This was an intended design by GameFreak (the makers of Pokémon) to encourage trading between different versions and friends.
Well if you dont have cheats or event codes, then there are 8 i think, dialga, cresilia,giratina,the three spirits(that you have to chase around),rotom,and heatran
By trading the other starters with other players of Diamond or Pearl.
Yes, if you have the three Regis, you can go to Snowpoint Temple and catch it at level 70 in Diamond and Pearl and level 1 in Platinum.
The three starting Pokemon to choose from in Pokemon Diamond are: Chimchar(Fire), Piplup(Water) and Turtwig(Grass).
No.
turtwig,piplup,and chimchar are diomonds three starting pokemon
they are chimchar, piplup and turtwig
either you get Pokemon emerald or Sapphire, and if you want them on diamond or pearl you have to beat the elite four and then migrate.