The Spitter

The Spitter is a new Special Infected to appear in Left 4 Dead 2.

It makes a hacking sound before spitting out what appears to be a ball of mutated phlegm, which upon hitting the ground spreads out similar to a Mortar round and changes from a sickish green gas-like substance to blood red. Any survivors within the area receive massive quantities of damage over time. This makes it exceedingly difficult to camp in one place for too long, otherwise the Survivors' health will slowly wittle away. It can be assumed the phlegm it shoots from its mouth has somewhat acidic properties, although it appears unable to pass through obstructions, even bouncing off hard surfaces such as walls. This brings to mind the question of whether or not the Infected could effectively spit at a wall from an angle and divert the phlegm to a camping group around the corner.

The Spitter was designed to split up tightly packed groups of survivors to make them easier to pick off by the other special infected.

Not much else is known about the Spitter; however, if the original Left 4 Dead campaigns are included in the sequel, it is questionable if they will be updated to include the Spitter, as it seems to be created specifically for the theme of the new campaigns.

Extent of Mutations
The Spitter's lower jaw, cheeks and lips seem to base either gone or noticeably eroded. This is most likely due to a mutation caused by the infection. The creature's body proportions are awkwardly stretched, including the elongated neck, and the belly seems slightly bloated, most likely to accommodate and produce the fluids.

It appears to be mutating in the same fashion as the Boomer, with its gut expanded, (probably still growing). It seems likely that, unlike the Boomer's bile, its spit can only cause damage, not attract the Horde.

Trivia

 * According to GameSpy, its graphics and design are still being worked on.
 * Some fans have come to give a nickname to the Spitter; "the Boomer's wife."