Answer: impostor

AnswerCrossword Clue
IMPOSTORQuack
IMPOSTORPretender
IMPOSTORFake
IMPOSTORIdentity thief, e.g.
IMPOSTORPhony
IMPOSTORCharlatan.
IMPOSTORPoseur.
IMPOSTORWolf in sheep's clothing, e.g.
IMPOSTORHuman phony
impostorA person who pretends to be someone else in order to deceive others, esp. for fraudulent gain
impostorone who poses as another to deceive, also IMPOSTER