Other forms: miscreants
A miscreant is a person who behaves badly — who lies, breaks the law, yells at puppies. It's a somewhat old-fashioned word, popular with old ladies shocked at having their purses stolen at the opera.
Words like miscreant, scoundrel, and good-for-nothing are used to condemn people believed to be improper or even evil. If your mom warns you that your friends are a bunch of miscreants, she's concerned that you're hanging out with the wrong kind of crowd and that you might be headed for trouble.