======The Lurker======

Based on data acquired from agents in the field, we have identified a biological monstrosity known colloquially as the Lurker. It appears to be a modified crocodilian with superhuman strength, speed, and endurance, making it difficult to take down in single combat. Of note are the eight arm-based structures featured on its back, giving it the ability to strike at and grapple with opponents in close quarters; the tail, which can be used as a striking surface; and of course its bite, which is unofficially suggested to be the strongest on record. Fortunately, the Lurker is not noted to have ranged attacks, although it can conceal itself underwater and is effective at stealth. 

Examination suggested that there may be more Lurkers in the tunnel system, including juvenile versions.