Most Skraylls live in the darkest forests, eating shrubs and rodents, although those that live a long time often grow larger and larger. Skrayll bones are made of a soft, rubbery substance that allows them to change over time depending on use, not unlike how muscles grow and shrink. Their rubbery bone material also secretes a slimy substance that hardens into a thick hide when exposed to air, which skyraylls must constantly shed or else they risk mobility problems and/or full paralysis.