After Prof. Oak recruited Crystal as his Pokedex Holder, Prof. Elm wanted Crystal to take this Chikorita as a partner on her journey. Crystal declined at the beginning since she had a full team, but Chikorita ran away from the lab and convinced Crystal itself to accept it. After seeing its determination, Crystal recruited it into her team. It evolved into a Bayleef while fighting a wild Larvitar on Mt. Mortar.