The Cornish describe the creature as a little person 2 ft 0 in (0.61 m) tall, with a disproportionately large head, long arms, wrinkled skin, and white whiskers.
As miners changed from independent, family-owned operators to hired laborers for large industrialized companies, there was an increased concern for safety, reflected in the knockers new role.
[5] To show appreciation, and to avoid future peril, the miners cast the last bite of their tasty pasties into the mines for the Knockers.
[6] In the 1820s, immigrant Welsh and Cornish miners brought tales of the Tommyknockers[7] and their theft of unwatched items and warning knocks to western Pennsylvania.
Even non-Cornish miners, who worked deep in the earth where the noisy support timbers creaked and groaned, came to respect the Tommyknockers.