You're chilling in your house then a knock comes from the front door. You go to check it out and there's no one but a box and a note

you read the note, saying that theirs a countryball inside

"dear stranger, we have bestowed you with a duty to breed and release as many countryballs as you can. They are becoming endangered species make sure to look after the ones you have and hatch!"

you looked at the box. What could be inside it?