Imp

An imp is a mythological being similar to a fairy or goblin, frequently described in folklore and superstition.

The Old English noun impa meant a young shoot or scion of a plant or tree, and later came to mean the scion of a noble house, or a child in general. Starting in the 16th century, it was often used in expressions like "imps of serpents", "imp of hell", "imp of the devil", and so on; and by the 17th century, it came to mean a small demon, a familiar of a witch. The Old English noun and associated verb impian appear to come from an unattested Late Latin term *emputa (impotus is attested in the Salic law), the neuter plural of Greek ἔμϕυτος 'natural, implanted, grafted'.

Originating from Germanic folklore, the imp was a small lesser goblin. Imps were often mischievous rather than evil or harmful (goblins in German legend were not necessarily evil), and in some regions, they were portrayed as attendants of the gods.

Imps are often shown as small and not very attractive creatures. Their behavior is described as being wild and uncontrollable, much the same as fairies, and in some cultures, they were considered the same beings, both sharing the same sense of free spirit and enjoyment of all things fun. It was later in history that people began to associate fairies with being good and imps with being malicious and evil. However, both creatures were fond of pranks and misleading people. Most of the time, the pranks were harmless fun, but some could be upsetting and harmful, such as switching babies or leading travellers astray in places with which they were not familiar. Though imps are often thought of as being immortal, many cultures believed that they could be damaged or harmed by certain weapons and enchantments, or be kept out of people's homes by the use of wards.

Imps were often portrayed as lonely little creatures, always in search of human attention. They often used jokes and pranks as a means of attracting human friendship, which often backfired when people became tired or annoyed of the imp's endeavors, usually driving it away.

...
Wikipedia