Tommy Knocker: The Underground Knacker
Cornish miners firmly believed in the existence of small, ugly, wizened, underground knackers or tommyknockers. They were thought to work alongside the miners in their own much smaller drifts, chipping away at the richest ore. To hear them in your mine was taken as a good sign, because they worked only the choicest ground. Knackers were forces to be reckoned with, however, and they often had to be appeased with a bit of pasty crust at lunchtime. Otherwise they might play pranks on you, such as causing a rock fall to cover your tools or they might pinch out a promising vein of ore.