Idiom
copycat
Theme: PEOPLE - NEGATIVE
a person who copies or mimics what someone else does. (Usually juvenile.)Sally wore a pink dress just like Mary's. Mary called Sally a copycat.Bill is such a copycat. He bought a coat just like mine.
Slang
copycat
Theme: MIMIC
n. someone who mimics or copies the actions of others.Don't be such a copycat. Find a style that suits you.Jim is a real copycat. He can say anything you say, just the way you say it.