This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Cetus (Greek)
A cetus was variously described as a sea monster or sea serpent. Other versions describe cetea as sea monsters with the head of a wild boar or greyhounds and the body of whales or dolphins with divided, fan-like tails. Cetea were said to be a colossal beast the size of a ship, their skulls alone measuring 40 feet in length, their spines being a cubit in thickness, and their skeletons taller at the shoulder than any elephant.
There are notable physical and mythological similarities between a cetus and a drak?n (the dragons in Greek mythology), and, to a lesser extent, other monsters of Greek myth, such as Scylla, Charybdis, and Medusa and her Gorgon sisters. Other images of the cetos in Central Asia influenced depictions of the Chinese Dragon and Indian makara.