Ruby, Sapphire and Emerald.
In Pokémon Ruby, you can only catch Treecko by selecting it as your Starter Pokémon if you picked Torchic or Mudkip as your Starter Pokémon then you cannot find it or receive it in the game however you can find someone else locally that would be able to trade you Treecko additionally you could have Treecko from Pokémon Sapphire and you could trade it over to Pokémon Ruby in order for Pokémon Ruby to get Treecko.
you have to beat the elite four and go to the pal park or transfer it from ruby,saphier or emerald
For Ruby, Mudkip. For Sapphire, Treecko. For emerald I do not know
After you fix the machine on 1 Island with the ruby and sapphire, it allows you to trade with the games emerald, ruby and sapphire. You can trade a Treeko from one of those games to FireRed.
at the pokemon lab
Torchic, Mudkip, and Treecko.
torchic,treecko and mudkip
from professor elm at the begining
Ruby, Sapphire and Emerald.
Trade it from Ruby,Sapphire,Or Emerald.
It's easier to trade for it
trade it over from emerald or ruby and Sapphire
You can receive a Treecko from Professor Birch in Pokemon Ruby, Sapphire or Emerald. To get it in other games you must trade it as it cannot be found in the wild.
Treecko or Mudkip. So do you liek mudkipz?
Torchic (fire-type), Mudkip (water-type) and Treecko (grass-type)
You can't breed treecko until it evolves to grovle or sceptile.