Native to New Zealand, the hagfish doesn't exceed one meter in length. It's a blind, jawless fish whose skeleton is limited to a few cartilaginous arches to which its head muscles are attached. Despite its appearance, the hagfish has a secret weapon. When attacked, it produces around 5 grams of mucin via glands on its flanks. On contact with water, the mucin instantly hydrates into a mucus, forming up to 20 liters of a viscous and very solid substance, which obstructs the mouth and gills of its predator.