A “drudging fiend,” and merry domestic fairy, famous for mischievous pranks and practical jokes. At night-time he will sometimes do little services for the family over which he presides. The Scotch call this domestic spirit a brownie; the Germans, kobold or Knecht Ruprecht. The Scandinavians called it Nissë God-dreng. Puck, the jester of Fairy-court, is the same.
Either I mistake your shape and making quite, Or else you are that shrewd and knavish sprite Called Robin Goodfellow. ... Those that Hob-goblin call you, and sweet Puck You do their work, and they shall have good luck.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894