Reptvile eggs are found deep within The Cave. Their unmistakable musty, rank stench is hard to ignore and can be used by spelunkers to determine just how far along they've explored the winding underground system.
Reptviles are small and sociable cave-dwelling lizards that cling to the side of cave walls in large numbers. Their combined bioluminescence generates a strong enough natural light source that can illuminate a pitch-black tunnel for many meters. An explorer made news headlines when, after having been declared missing for several days, he reemerged and claimed that a population of Reptviles guided him safely out of The Cave.