Valve has announced the latest mutation game mode in Left 4 Dead 2: Last Gnome on Earth. In order to win, the survivors simply have to carry the garden gnome through any of the single-player campaigns. There's a catch though: the Infected will immediately swarm on anyone carrying the gnome. Valve also warns players to be careful setting the gnome down as "a boomer explosion will send him flying." The mutation is only available in campaign mode.

Valve also added that Realism Vs mode, as promised, will become permanent starting next week for everyone that owns "The Passing" DLC. Furthermore, one of the mutations released so far will make a comeback next week, with Valve noting that the mutation will be voted in by players. The candidates include Follow the Liter, Bleed Out and this week's mutation, Last Gnome on Earth. Finally, Valve will be playing Left 4 Dead 2 with the community this weekend. Check out a list of Steam and Xbox Live gamertags the team will be using after the break.