a bad penny always turns up
A person with no value always returns. I'm sure we haven't seen the last of your conniving cousin—a bad penny always turns up, after all.
bad penny always turns up
Prov. A worthless person always comes back to the place he or she started out. Jill: I just found out that Tom left town after we fought last Saturday. What if I never see him again? Jane: Don't worry. A bad penny always turns up.