Nouns

(n)monkeyany of various long-tailed primates (excluding the prosimians)
(n)imp, scamp, monkey, rascal, rapscallion, scalawag, scallywagone who is playfully mischievous

Verbs

(v)tamper, fiddle, monkeyplay around with or alter or falsify, usually secretively or dishonestly“Someone tampered with the documents on my desk”, “the reporter fiddled with the facts”
(v)putter, mess around, potter, tinker, monkey, monkey around, muck about, muck arounddo random, unplanned work or activities or spend time idly“The old lady is usually mucking about in her little house”