I am that merry wanderer of the night.
I jest to Oberon and make him smile
When I a fat and bean-fed horse beguile,
Neighing in likeness of a filly foal.
– William Shakespeare
A Midsummer Night’s Dream, Act 2, Scene 1. Puck says this to an unnamed fairy who identifies him as the mischievous sprite. Puck doesn’t deny his infamous reputation for wickedness. Rather he boasts about it, describing the role he performs for Oberon, which is like that of a jester, though a magical one. In the example he gives here, he makes the Fairy King smile by tricking a fat, well-fed horse by neighing as if Puck were a young filly.