Your adopting a Pokemon and talk to the gal in the front of the adoption center

Front-Desk Woman: "Hi! Looking to adopt a Pokemon?" You: "Yes. I wanna know if you guys have any Lucarios?" Front-Desk Woman: "Well. You're in luck! We have one more! But I don't know how much you'll like This one in particular. Come."

You follow behind

Front-Desk Woman: "Well. Here he is."

The Lucario is wearing a diaper and they hear the voice and look over

Front-Desk Woman: "He's not really.. Potty-Trained yet. If you're fine with that.. You can try to get him Potty-Trained if you want but good luck"