Worm

Worms are the enemies in SAS 4 that, despite the name, looks like green slugs encountered by killing a Bloater. In game they are mentioned as "Secondary larval parasites" in the Bloater description, meaning that worms lives inside Bloaters, using them as host. Generaly found by killing a Bloater, them can also be encountered living freely through the places, though. A example of this is in the mission Vaccine, when the player get in the train, there will spawn several worms in the third wagon.