Impossinator 

(Im-poss-ə-na-tor)(s) (noun)
(Im-poss-ə-na-tions) (plural noun)
A person or persons who are adept or highly skilled at impersonating famous personalities (for comedic purposes) from throughout history.... which is nearly (impossible) past 150 years ago up until photography an sound recordings were invented...or a person up to our current time...(impostor) if the person who is being mimicked is still living...but truly it is impossible to exactly impersonate someone or something strictly by skilled acting alone a full 100%, which would not really be as funny anyway if at all thus a noticeable difference is to be maintained in order to be considered as even possibly comical.

That overly ridiculous impossinator tried in vain to sqeeze the smallest hint of a laugh from those impossible critics.

Impossinator by Elworth Haygood February 14, 2019

Imposinator 

1) One whom pretends to be one pretending to be someone else.

2) One impersonating someone who is an impostor of another

3) Of, or pertaining to, the act of pretending to be someone who is pretending to be someone

Did you guys see Tosh's performance of the Tron guy? Yeah, that guy is such an imposinator.

Imposinator by Phakade July 24, 2010