Tommyknockers (whom the Dwarves call Kobolds) are of the earth, and dwell in caves and mines. They communicate over long distances by knocking on pipes and cave walls (hence the term Knockers). They are known for causing cave ins, and otherwise creating mischief for miners.
Redcaps are solitary Goblins who favor inhabiting the ruins of human civilization. They get their name from their habit of dying their caps in their victim's blood.
Hobgoblins are goblins of the wood. They live within trees and hillsides in dark forests, and venture out mostly at night. They are most active during the new moon. Hobgoblins have a propensity for abducting small children.
Kelpies are water Goblins, and tend to be solitary. They lure humans to the water either to be their mates and servants or to meet a watery death. They are shapeshifters, and often take the form of horses.
The Pooka is a Goblin of air, which like the Kelpie has the ability to shapeshift.
The Mandragora is a Goblin of fire.