A subset of the "Evil Twin", these villains actually pretend and claim to be the character they resemble with intentions typically including getting close to the person's friends/family so that they can then betray or harm them in some fashion, or ruining a hero's reputation by doing bad things while under their guise. They are often very good actors up to the point that no one would suspect them of being a faker, leading to the wrongful arrest of the real person if the antagonist is an incriminator, or an accusation of being an imposter or something else evil being harshly frowned on without strong evidence.