In folklore and fiction, a goblin is a kind of monster. Precisely what a goblin looks like, how it behaves and what its abilities are vary from story to story.
The origin of the word "goblin" is unknown. It may derive either from the German Kobold or the Welsh coblynau, both of which refer to ghostly creatures, similar to poltergeists, which are said to enjoy playing tricks on people and to irritate them by making noises.
Goblins are often depicted as being similar in appearance to humans but with exaggerated features, such as large noses and large pointed ears. Their skin may be an unusual color, such as green. Goblins are usually imagined as being small. Depending on the story, they may be slightly shorter than the average person or they may be only a few inches tall, making them almost invisible to the naked eye. They are sometimes said to possess magical powers. Goblins are often said to be mischievous and sometimes to be thoroughly evil. In some stories, goblins are depicted as greedy, money-loving creatures.
Another type of goblin is the hobgoblin, which is most often depicted as a separate entity, sometimes evolved from regular goblins in some manner. Sometimes goblins are also interchangeable with imps.
In modern fiction
The words "goblin" and "orc" are used almost interchangeably in J.R.R. Tolkien's The Hobbit and The Lord of the Rings, although "goblin" is generally used to refer to smaller creatures in those novels. Tolkien's depiction of goblins, as creatures similar in size and shape to humans but much more repulsive in both appearance and behavior, greatly influenced later writers of fantasy fiction and creators of role-playing games and video games.
In the novels in J.K. Rowling's Harry Potter series, goblins are short humanoid creatures with dome-shaped heads and long fingers and toes. Some of them have dark slanted eyes. They have magical abilities which are different to those of witches and wizards and do not require a wand in order to perform magic. They are gifted silversmiths and make the coins that witches and wizards use. They run Gringotts Wizarding Bank and control the wizarding world's economy to a large extent. Many witches and wizards consider goblins to be inferior and wrongly imagine that goblins accept that they are.