The Smoker

From wikipedia

An Infected with a long, whip-like tongue that can drag Survivors away from their team-mates and use its tongue as an organic noose to strangle Survivors when it is perched on a rooftop. Similar to Half-Life's Barnacle, or Resident Evil's Licker. When in danger, it can leave a haze of black smoke, distorting the Survivors' vision.