The aggressive quil crawl upon a multitude of legs, sliding across the ground in an undulating fashion. A thick coat of bony spikes covers their broad backs, laying flat during movement, but when threatened, they rise on end. They have a dozen insect-like legs and an armored head that can retract beneath the creature's torso if needed. Their head is bone, with no skin, and their jaws open and close like a vise, able to tear through flesh, clothing, furs, and even armor. Their finger-like claws are able to grasp things, allowing them to eat them all the faster.

Infestation. These multi-leg creatures are the bane of farmers, villages, towns, and dungeons. They thrive upon any organic matter, whether flesh or plant. They live in any clime but are most active during the warm months when crops are coming in and markets are filled to capacity with fresh food. Then the quil swarm in pods of a dozen or more. If left unchecked they infest areas, often driving out the local inhabitants.

Colonies. On rare occasions, the quil nest in huge colonies, where an adult female allows other quil to attach upon her, they fold themselves up in a giant ball, breeding and feeding upon each other. If the nest is attacked, there can be scores of the creatures, all of whom drop to the ground and attack.

Persistent predators. The quil's spikes protect it from most predators, designed to hold off an attacker while the quil devours its meal. They are very agile though, and if persistently attacked, or even one of their pack is persistently attacked, they become very aggressive, attacking with their vicious bite.