The Boomer



The Boomer is an extremely bloated Special Infected, which seems to have been filled with an odorous slime. They are able to projectile vomit this bile, and if it hits the Survivors, it covers them, temporarily blinding them and attracting the Horde. When the boomer dies, it explodes and discharges large amounts of gore and viscera, which will also attract the Common Infected if an unfortunate Survivor is caught in the blast.

Boomers are relatively delicate, as far as the Special Infected go: it is only able to take a very small number of bullets before it bursts. If a Boomer drops from a particularly high place, such as from a roof top into a street, they "pop," which is an effective manner of ambushing Survivors.

In versus mode, players are able to play as Boomers. Their ability to vomit is gauged by a somewhat slow-filling meter, which was probably employed to balance gameplay. Though the Boomer is clearly not one for combat, its melee attack can deal double the damage of a regular infected, much like the other boss infected. It's recommended to begin hitting Survivors if you've already vomited on one or more. If they aren't careful, it's possible that they will cause the player to burst, covering any clean Survivors left. Only one Boomer is allowed while on the Infected team in Versus.

Extent of Mutations
The Boomer has been heavily mutated by this strain of the infection. It has become extremely bloated to the point that a slight rupture in its flesh will cause it to explode in a bloody, bile-filled explosion. It is unknown whether it was the result of the infection of an incredibly obese individual or the result of a strange strain of the infection. Massive growths have appeared along its skin, indicating that it may still be expanding. It has developed the ability to vomit from great distances, and its bile has developed the unique characteristic of attracting all nearby infected in the surrounding area, possibly through smell. Though its mentality is similar to that of the typical infected, it not distracted by such things as the flashing lights of pipe bombs nor is it apparently attracted by such things as car alarms going off.

Survivors
General:
 * Listen for the heavy breathing, gagging sounds, and the music cue that heralds the presence of a Boomer.
 * Keep an eye out for defensive positions, that way you'll be ready if the Boomer blinds you.
 * Avoid being too bunched up with the other survivors (i.e.: no sense all four getting stricken at once).
 * On expert finding and killing the Boomer before he can vomit or explode is incredibly crucial as the boomer bile attracts the horde, which on expert difficulty is incredibly more dangerous than any other difficulty.

Before bile spit or Boomer death explosion:
 * If the Boomer is too close, it's a good idea to melee it (which will push it back to some degree) then back away to a safe distance (approx. 25 feet away) before shooting or you'll get covered in bile, even though you weren't vomited on.
 * CAUTION: You can only safely push a Boomer back twice; a third time will cause him to explode.
 * If the Boomer is sufficiently far away from both yourself AND all other survivors, only then should you shoot it.

After getting slimed:
 * Know that a massive horde will immediately descend upon you (and any others who have been slimed).
 * Hold your fire! Since you can't see, friendly fire is the most likely result. You need to:
 * Run to a defensive position (corners and doorways are particularly good).
 * Crouch! Other survivors will be able to shoot over you safely if you do so.
 * Use melee continuously to survive the incoming zombie horde.
 * Once your sight starts to clear, mop up with your weapon.

Helping a slimed survivor:
 * Stay close to the stricken survivor
 * Help melee the horde back or shoot if the blinded survivor stays safely crouched

Infected
While it may be difficult to be completely stealthy as a Boomer, try to hide in shadows, around corners, or within crowds of Common Infected. To ensure that you slime the Survivors, vomit on them at close range, then run up to attack them so that they will be more likely to shoot you. You will explode and spread the bile within a certain radius. Your best teammates are the Special Infected.


 * First and foremost, the Boomer can only spawn one wave of infected, per survivor, at a time. Vomiting on a survivor and then exploding on the same survivor will not generate additional infected despite getting one person "twice." To generate additional infected, you must either explode on a "non-purple" survivor, or wait until all survivors are no longer surrounded by a purple aura with bile and then strike again. Therefore; he who pukes and runs away, lives to puke another day.
 * Boomers are slow and large, making them easy targets so if you manage to slime a group of survivors in a place where running away is going to be difficult, and finding cover will take some time. Don't be afraid of running in and clawing them, as this will deal extra damage. While in the middle of the chaos, it can also confuse the survivors from which direction the horde are actually attacking them from. Also, if they're not careful, they can shoot you once they're clean, resulting in being covered again.
 * The Hunter can pounce on the Survivor covered in bile to add terrible confusion to the mess; the bile will summon the infected, who will create a meat shield for the Hunter. By the time the other survivors are able to get to their pinned friend, it may be too late.
 * The Smoker can constrict a Survivor who has been covered, effectively creating a pinata for the Common Infected.
 * The Tank can distract those who are not covered in bile, cutting them off from helping their friend. It can also incapacitate a covered Survivor, rendering them nearly helpless against the zombie onslaught all over them and adding the chance that they'll bleed out.
 * While a Survivor is covered in bile, they cannot see the outlines of the other Survivors. While another Infected is attacking a straggler, take the opportunity to cover the other Survivors with bile.  While this may cause the Horde to spread out, it is important to impair the other Survivors' vision so that it becomes more difficult for them work together and to aim.
 * The Boomer can hide beside cars with alarms and near Witches to trick Survivors into shooting them. The nearby explosion will cause the alarm to be triggered or the Witch to be startled.
 * Waiting behind doorways and in small rooms will guarantee at least one successful slime.
 * If you are stuck outdoors, hide in a place where the survivors cannot see you and wait for them to be distracted by something else then run in and vomit.
 * Vomit on incapacitated survivors.
 * Vomit on survivors pinned by hunters or smokers.
 * Hunters are a great distraction and can let you close the distance without being noticed.
 * In areas with alley ways or other high roofs, jump down into the middle of the survivors. You'll either be shot in surprise or get an excellent chance to vomit on all four survivors in quick succession.
 * You can also stand on rooftops and barf down on the survivors. Gravity will help the bile to reach them even from great heights.
 * Don't hide right next to thin walls. Not only can survivors shoot through most of them, your ample mass may stick through, giving them a free kill. The slime from the aftermath will, unfortunately, be unable to get through. Try to hide slightly off the wall to minimize cheap kills.
 * Speaking of cheap kills, let a hunter melee you four times before you charge a survivor. They melee you, you pop.
 * When you pop, you knock people back. This includes but is not limited to survivors, common infected, Hunters who have pounced on survivors, Smokers constricting survivors, and Tanks. The good news is that you can knock Survivors off of high ledges; the bad news is that you can do the same thing to Tanks. Take care where and when you explode!
 * Also note that other infected (both common and special) can accidentally block your puke from hitting your intended targets.

Survivors
Blind Luck You or another Survivor take no damage after being vomited on by a Boomer.

Clean Kill Shove a Boomer and then kill him without him splashing on anyone.

Stomach Upset Survive an entire campaign without any survivors getting covered in Boomer bile.

Outbreak (Only For PC) Catch a rare strain of infection, then pass it on to someone else.


 * The "Outbreak" achievement is unlocked by being vomited on by a player who already has that achievement.

Infected
Barf Bagged Cover four Survivors with Boomer bile at once.

Trivia

 * In the game's commentary, it's mentioned that originally the Boomer's explosion simply caused damage to nearby players, and that the horde-attracting abilities were assigned to the Screamer, another Special Infected that was cut from the final game. When the Screamer was dropped, the screams that formerly attracted the Horde were changed to the Boomer's bile.