jackanapes

jackanapes \JAK-uh-neyps\, noun:

1. An impertinent, presumptuous person, especially a young man; whippersnapper.
2. An impudent, mischievous child.
3. Archaic. An ape or monkey.

I blame those jackanapes on the council…
-- George R. R. Martin, A Song of Ice and Fire

The long-established practitioners, Mr Wrench and Mr Toller, were just now standing apart and having a friendly colloquy, in which they agreed that Lydgate was a jackanapes, just made to serve Bulstrode's purpose.
-- George Eliot, Middlemarch

Jackanapes is a circuitous eponym. In the 1300s, it literally meant "jack of the apes" and was the nickname of William de la Pole, Duke of Suffolk, whose badge was an ape's clog and chain. The word acquired the sense of "mischievous boy" two hundred years later.