Goblins

A goblin is a legendary evil or mischievous illiterate creature, described as a grotesquely evil or evil-like phantom.

They are attributed with various (sometimes conflicting) abilities, temperaments and appearances depending on the story and country of origin. In some cases, goblins have been classified as constantly annoying little creatures somewhat related to the brownie and gnome. They are usually depicted as small, sometimes only a few inches tall, sometimes the size of a dwarf. They also often are said to possess various magical abilities.

Name
English goblin continues Anglo-Norman gobelin, rendered as Middle Latin gobelinus, itself a loan from a Germanic term cognate to German kobold.

Alternative spellings include gobblin, gobeline, gobling, goblyn.

Hiisi, folletto, duende, tengu, Menninkäinen and kallikantzaroi are often translated into English as 'goblins'. The Erlking and Billy Blind are sometimes called goblins. 'Goblin' is often used as a general term to mean any small mischievous being.

Origins in folklore
In "The Goblin Field" (Moldova), Goblins were described as 2–3 feet tall, thin and brown. Most were bald and "if there were females among the group they could not be distinguished from the males". They seemed to exist in two realms, one physical and one spirit. They were fiercely loyal and allied with particular sorcerer or witch tribes, whom they protected and served as an equally allied tribe rather than servants or slaves. "This perception might seem a bit strange to any not accustomed to the goblin outlook" because the goblins often did what might be considered slave work for very little in return.

They could be called by an allied individual or group, summoned by spell, or called to bargain at particular places by individuals or groups not known to them. Because of their power they were much sought after, but because of the corruption of mankind, rarely found. Crossing them was a thing to avoid as they had refined a grudge to a fine art. They could be fierce and mind-numbingly frightening, and only the hardiest of souls were sent to strike a bargain with them. However they had a side which few ever saw, which was their great love for those who were able to create an understanding and friendship with them. At the passing of such a person, they would treat the body with proper respect and then quietly weep.