A person who imitates or adopts the behavior, style, or ideas of someone else. The new artist was criticized for being a copycat of more established painters.
An imitation or replica of something, especially when made with the intent to deceive or replicate the original. The designer handbag turned out to be a copycat, not the genuine article.
A crime, especially a violent one, that is carried out in imitation of a previously publicized crime. Police feared the shooting could spark further copycat crimes.