Bluecap

Bluecaps are a type of small fairy or spirit which originate in the folklore of the Scottish Borders.

Overview
Appearing as a small blue flame, the Bluecap was said to be an inhabitant of mines and delvings. If treated well and with respect, they would guide the miners to the richest deposits of gold and minerals, and were even known to use their precognitive powers to warn them of impending catastrophes such as floods or cave-ins.

An unusual aspect of the Bluecaps was that they wished to be paid the same amount as a regular human mine worker. This wage would be left in a secluded part of the mine for the Bluecap to collect, and the little creature would not accept any more or less than the correct salary.