If you want a serious answer... [spoiler]Adopting it is unwise. It's a lot less money for you on account of caring for it and it could take a long time to potty train. The wisest idea is to call a local shelter that will take him/her, one that doesn't "put out" overdue residents and has a good chance of finding your mystery dog a home. If this fails, you could try and see if a trusted friend might take him/her in, though this is unlikely. Lastly, you could try and sell him, but this is incredibly risky and unadvised, this is a LAST RESORT METHOD. To avoid this course of action, it might work to care for the dog a short time until a shelter or someone you trust accepts it, but there's always the heartbreaking risk of getting attached.[/spoiler] If you want a stupid and unnecessarily sarcastic answer that isn't even funny... [spoiler]Look at literally any other comment from literally any other person.[/spoiler]