In HGSS, Mr. Mime could be found in Route 21. Referring to the anime episode.
Huh?Mr....Ahhh!You can spend the night over at our house.Do you have somewhere to go?KotoMr. Mime!It's getting dark...Hahaha. Good for you.Thanks for the meal!BuhaaaMr. Mime!
Mr. Mime!Hey, Mom. I feel sad for it.Let's see now...