fox’s tail—something that gives away a person’s real character or evil intentions
狐狸尾巴
the fox has shown its tail (or displayed its cloven hoof);sth that gives away a person's real character or evil intentions
狐狸尾巴hú lí wěi bā
传说狐狸能变成人形以迷惑人，但其尾巴怎么也藏不起来。比喻坏人的本来面目或罪证。sth. that gives away a person’s real character or evil intentions, cloven hoof, fox’s tail