You cannot catch a wild Chikorita. It's extremely rare to be able to catch a Starter Pokemon in the wild as players are almost never given the chance to. This was a design choice to encourage trading between games and player interaction.
Chat with our AI personalities
You cannot catch wild Chikoritas in any official Pokemon game.
Unfortunately, you can't catch a Chikorita in the wild. You'll only be able to find it if you choose it as your Starter Pokemon or you chose a Totodile as your Starter (in which your rival will choose the Chikorita). Or you can trade another Pokemon for it in the GTS.
Your only chance to get a chikorita in the game is by choosing it as a starter Pokemon. Chikorita cannot be caught in the wild. It cannot be obtained through in-game trades, either. You must trade to get it from another person (via Wi-Fi or wireless local communications).
You can't you have to migrate
season 3 ep 10.