Goblin
Goblins are mythological creatures of unclear origin and contradicting descriptions. They are small humanoids of a mischevious nature, possibly belonging to the fey family (along with creatures such as redcaps, brownies, leprechauns, kobolds etc.)
In modern fantasy the term goblin has been very much determined by the Tolkienian use of the word - as in, a smaller variant of the orc species. Goblin appearance has been further shaped by both video- and boardgames, and various artists. They are universally smaller than humans, although the exact size varies, and often have large pointy ears (larger and more animalistic than elf ears) and either long, crooked and pointed noses or orcish nose-less features.
The typical goblin stereotype is that of a savage warrior and raider that attacks villages and ambushes unwary travellers. They act and move in smaller groups as they don't pose a large threat by themselves. Goblins tend to live in caves and gang up with orcs and similar races, which they are sometimes described as belonging to the same family or species.
Other games and stories feature different kinds of goblins. For example both Warhammer(40k) and Warcraft goblins have a penchant for technology and love to tinker with machinery (steampunk contraptions and the like), somewhat propagating the "mad scientist" archetype. In Eberron, goblins are the descendants of a once mighty kingdom instead of simple savages. In Pathfinder, they're stupid little freaks with all manner of strange quirks (good singing voices, fear horses and writing, like fire and pickles), sort of a cross between Gremlins and a baby-eating Stitch.
See also
- Unified_Setting/Goblins Yet another take on a classic concept.