One who opens or exposes.

A person who imitates or mimics others, often in a mocking manner.

नकल करने वाला

English Usage: He was an aper of famous personalities, often imitating their mannerisms.

Hindi Usage: वह प्रसिद्ध व्यक्तियों का नकल करने वाला था, अक्सर उनके व्यवहार की नकल करते हुए।