Ouroboros
Near Life Experience says: "The Armadillo Lizard adopts a curious defensive posture when threatened by rolling itself up like an Armadillo, with its tail tightly held in its jaws, presenting a spiny ring to the predator and protecting the softer, vulnerable belly area."
Ahoy, the Ouroboros: "The Ouroboros, also spelled Ourorboros, Oroborus, Uroboros or Uroborus (pronounced /ˌjʊəroʊˈbɒrəs/), is an ancient symbol depicting a serpent or dragon swallowing its own tail and forming a circle. It has been used to represent many things over the ages, but it most generally symbolizes ideas of cyclicality, unity, or infinity. The ouroboros has been important in religious and mythological symbolism, but has also been frequently used in alchemical illustrations. More recently, it has been interpreted by psychologists, such as Carl Jung, as having an archetypical significance to the human psyche."