Goblins are a rather small and typically weak species compared to many of the other humanoid races.
Most goblins act like enemy mobs attacking randomly however some are more reasonable or even have some semblance of a civilized culture. Well civilized in a goblin sense of the word.
Goblins have many variations from the basic goblin to the stronger hobgoblin in addition to others.
Worlds that are known to have various forms of goblins are as follows:
Interworld System of Planets
.hack
Digimon
Final Fantasy Universe
Hell
InuYasha
Magic
Oblivion
Phantasy Star
Purgatory
Shadowverse
Skylanders
Yu-Gi-Oh
Folklore