Entozoons are native to Ghenla and are immense grublike creatures that live in the caves of the Amber Ridgeline. They have shells of hardened ambergris that has achieved a rocklike consistency. They are of interest to scientists both for their carapace (which, when sufficiently aged, is useful in the creation of fine perfumes), and for the fact that they seem to have no end to their natural lifespan, and do not seem to age as normal creatures do. They begin life in the ocean, and consume the smaller blood darters that nest in the ridgeline.