Monster (also VMS Monster) is an MUD-like game developed for VAX/VMS in the late 1980s. It is known for being one of the first multi-user games to feature an early version of what later became online creation. In Monster, players can "fight, talk, trade items and explore territory together". Game administrators are also able to "create objects, make locations, and set up puzzles for other players to solve". What is notable is that there are no NPCs in the original version of the game.