Night on the ground on Skull Island is a dangerous time and place to be if you are small. Among the invertebrate predators, few had jaws that could compete with those of the Moonspider. A variety of Sunspider (actually called solifuge), not a true spider but still an arachnid, the ten-legged Moonspider sports huge crushing mandibles and paralytic venom to make short work of its prey. Rodents, lizards, ground birds, and even dinosaur chicks were potential victims. A bite from the sizable arachnid can cause significant discomfort to even an adult dinosaur. Moonspiders hunt at night to avoid becoming prey to diurnal birds and other large hunters.
A particularly nasty tactic developed by Moonspiders is to wait near dinosaur nests just as young are hatching. Tuned to pick up the faint scent of egg matter on a night breeze that might indicate the early stages of a hatching, Moonspiders are drawn to nests where young are still struggling to free themselves from their shells. In this vulnerable state they are easy prey for the invertebrate.
Moonspiders are nasty little predators that are the only truly invincible enemy in the game (other than adult Vastatosaurus rex when confronted by humans), as shooting has no effect. They kill with only one attack. The only way to evade them is to bait them away with a captured dragonfly, larva, or baby swampcrawler, or even a slain enemy animal like a Megapede, but throwing a spear on fire will also disperse them to pass safely. If Kong leaves Ann unattended and begins to wander, Moonspiders will attack her.