In German (Teutonic) folklore, kobolds are spirits who dwell
in mines and who like to torment humans. They are tricksters
and not inherently evil. Like Robin Goodfellow, they
may either help or harass humans, for unknown reasons.
the 16th and the 17th century, they were usually depicted
on paintings as little devils with a conical hat, pointy
shoes, a hairy tail, and bald feet instead of hands.
In the class of fairy-like beings, they are considered to
be the most dangerous and most ugly.
sources suggest that kobolds are related to the Brownies.