A mob, short for mobile or mobile object, [ 1 ][ 2 ][ 3 ][ 4 ] is a computer-controlled non-player character (NPC) in a video game such as an MMORPG [ 5 ] or MUD. [ 1 ][ 3 ] Depending on context, every and any such character in a game may be considered to be a "mob", [ 2 ][ 1 ] or usage of the term may be limited to hostile NPCs and/or NPCs vulnerable to attack.

In video games, a "mob" refers to a mobile character or entity controlled by the computer or AI. It is short for "mobile," since mobs can move around within the game. In most cases, mobs are enemies, such as monsters or creatures, that a player must avoid or destroy. However, they can refer to other moving objects within a game as well.