Mob
From WoWWiki
A mob (short for mobile or mobile object) is a non-player entity whose primary purpose is to be killed for experience, quest objective, or loot.
The gaming term "mob" is not to be confused with its usual meanings in the English language, i.e. a large disorderly crowd or an organized gang of criminals.
Mobs are also known as bad guys, beasts, enemies, monsters, non-player attackers, and opponents. The World of Warcraft-specific term for a mob is creep, coined by Blizzard and first used in Warcraft III. The term mob is in wide-spread use in the MMORPGs genre.
Etymology
The term was originally used in Multi User Dungeons (MUDs) the text-based precursors to MMORPGs. In-game objects were defined either as stationary items - "objects" (ranging from fountains to wearable equipment that you could pick up) or "mobs" (this included any NPC, be that aggressive monster or friendly shopkeeper, even if they weren't actually moving around due to STAY_ROOM or similar flags in their properties).
In World of Warcraft Mobs differ from NPCs in that they are usually monsters that share a common name with several others rather than having a unique name or title, are non-friendly, are non-interactive, and/or exist solely for the purpose of being killed. These are the main aspect of PvE, and are found throughout the game world.
