If you describe someone as puckish, you mean that they play tricks on people or tease them. He had a puckish sense of humour. = impish. showing that you are amused by other people, and like to make jokes about them (Puck evil spirit in old English stories)
[ 'p&-kish ] (adjective.) 1874. After Puck, a mischievous fairy in English folklore who is also a character in Shakespeare's A Midsummer Night's Dream.