puck

puck, in medieval English folklore, a malicious fairy or demon. In Old and Middle English the word meant simply “demon.” In Elizabethan lore he was a mischievous, brownielike fairy also called Robin Goodfellow, or Hobgoblin. As one of the leading characters in William Shakespeare’s Midsummer Night’s Dream, Puck boasts of his pranks of changing shapes, misleading travelers at night, spoiling milk, frightening young girls, and tripping venerable old dames. The Irish pooka, or púca, and the Welsh pwcca are similar household spirits.