Jack is an archetypal Cornish and English hero and stock character appearing in legends, fairy tales, and nursery rhymes, generally portrayed as a young adult. Unlike moralizing fairy heroes, Jack is often portrayed as lazy or foolish, but through the use of cleverness and tricks he usually emerges triumphant. In this way, he may resemble a trickster.
Some of the most famous include "Jack and the Beanstalk", "Jack Frost", "Jack the Giant Killer", "Little Jack Horner" and "This Is the House That Jack Built". While these heroes are not necessarily congruous, their concepts are related and in some instances interchangeable. The notion of "Jack" is closely related and sometimes identical to the English hero John. He also corresponds with the German Hans (or Hänsel) and the Russian Iván.
"Jack Tales" are also popular in Appalachian folklore. Richard Chase, an American Folklorist, collected in his book "The Jack Tales" many popular Appalachian Jack tales as told by descendents of Council Harmon. Council Harmon's grandfather, Cutliff Harmon, is known to very possibly be the one who originally brought the Jack tales to America. As pointed out by folklorist Herbert Halpert, the Appalachian Jack tales are an oral tradition as opposed to written, and like many Appalachian folksongs, trace back to sources in England. For instance, where the English original would feature a king or other noble, the Appalachian Jack tale version would have a sheriff. Some stories feature Jack's brothers, Will and Tom. Some Jack tales feature themes that trace to Germanic folk tales.