You beat every stage in that map thing and when your at the concert kill anything and don't die in till the copper is their
This is a guess but think it's either dark carnival or the parish
Swamp Fever. The Parish. Hard Rain. Dark Carnival. Dead Center.
There are no bosses in L4D2 but you should encounter at LEAST 2 tanks.
Pre Order from Game Stop or find it in the Dark Carnival
You get him from a shoot-out game on the second level of Dead Carnival.
Assuming you're including the DLC (As of 2013) No Mercy, Crash Course, Blood Harvest, Dead Centre, The Sacrifice, The Passing, Dark Carnival, Swamp Fever, Hard Rain, The Parish. (Campains not canon in the story line) Dead Air, Death Toll, Cold Stream. (Not Including L4D1 Crossover DLC) Dead Centre, The Passing, Dark Carnival, Swamp Fever, Hard Rain, The Parish. (No DLC) Dead Centre, Dark Carnival, Swamp Fever, Hard Rain, The Parish.
5 campagins and 4 multiplayer modes in total the campagins are called: The Parish Dead Center Dark Carnival Swamp Fever Hard Rain Hope i helped :)
Do the campaign Dark Carnival, choose the level barns and as you get through the level you will see a wack-a-mole machine. Start the machine and hit the moustachios until the machine overloads.
gnome chopiliski or i cant spell its name its a gnome you try to win in the left for dead 2 dark carnival part 2 you can use it to wack zombies and if you last 5 levels until you survive and beat the concert with gnome chopoliki you get an acheivement it will be hard make sure you take your time and try to find gnome chopoliski
there is Dead Center, Dark Carnival, Swamp Fever, Hard Rain and the Parish and in the spring of 2010 the Passing will be released where the l4d2 survivors meet up with the l4d1 survivors
(CAUTION: This answer contains information that may spoil the campaign(s) if you have not yet played them.) They meet in between the Left 4 Dead 2 campaigns Dead Center and Dark Carnival in a download-able campaign called "The Passing", which is soon after the campaign for both Left 4 Dead 1 & 2, The Sacrifice. The Left 4 Dead 2 survivors are driving through an infected town and the bridge is out, Francis or Zoey will tell you that you have to gas up a generator to get across because it has no energy left from when they raised it. Louis has a hurt leg so they can't leave him alone, and Bill got taken out by a few tanks, you will see the bloody result in the room of the scene. In The Sacrifice, where you play as the original survivors, any one of the survivors can sacrifice themselves to restart the malfunctioned generator to raise the bridge, but it will always appear as Bill in The Passing.
Left 4 Dead 2!!