Jane/John Doe
Jekyll and Hyde
Johnny-come-lately
persona no identificada, N.N.
Jekyll y Hyde
advenedizo
Who is this John Doe that keeps sending me anonimous letters and flowers?
Bill is like Jekyll and Hyde: one minute he's fine, the next he's screaming and shouting.
He's just a Johnny-come-lately: he's been here for two weeks and he's already manager!