This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Scitalis (Medieval Bestiaries)
The Scitalis or Scytale is a serpent from Medieval bestiaries, such as the Aberdeen Bestiary, supposed to have such marvelous markings on its back that its appearance would stun the viewer, slowing the person down so that they could be caught. Its bodily heat was so great that it shed its skin even in the winter.
Isidore of Seville wrote in the 7th century AD, that "The scitalis (scytale) has a skin that shines with such variety that by these marks it slows down any who see it. It creeps slowly and cannot pursue its prey, so it stupifies with its marvelous appearance. It is so hot that even in winter it sheds its skin."