Mischievous. (adj.) a person who is mischievous causes annoyance and minor harm or damage. Showing a playful desire to cause trouble.
e.g. The children had been so mischievous that we had to pay the babysitter extra to clean up the mess.
Son of a gun: (n.) a person ( usually a boy) or a thing that you are annoyed with. (check other meanings for more info.)
e.g. That son of a gun broke the TV!!
( also used as a mild alternative to " son of a bitch" )
Rascal. (n.) a person ( especially a young person) who causes trouble or does things to annoy people. (Check other meanings for more info.)
e.g. You Little Rascals! I saw you switching the sugar with the salt!