monkey

(noun) any of various long-tailed primates (excluding the prosimians).

(noun) one who is playfully mischievous. Synonyms: imp, scamp, rascal, rapscallion, scalawag, scallywag.

(verb) play around with or alter or falsify, usually secretively or dishonestly. Synonyms: tamper, fiddle. Examples: "Someone tampered with the documents on my desk." "The reporter fiddle with the facts."

(verb) do random, unplanned work or activities or spend time idly. Synonyms: putter, mess around, potter, tinker, monkey around, muck about, muck around. Example: "The old lady is usually mucking about in her little house."