This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Sea-Wyvern (Heraldic)
The sea-wyvern lives in the sea and has a fish tail in place of a barbed dragon's tail. The wyvern (sometimes spelled wivern) is a type of mythical dragon with two legs, two wings, and often a pointed tail which is said to be a venomous stinger. A wyvern is typically depicted resting upon its legs and tail, but may be depicted with its claws in the air and only supported by its tail.
The wyvern in its various forms is important in heraldry, frequently appearing as a mascot of schools and athletic teams (chiefly in the United States, United Kingdom, and Canada). It is a popular creature in European literature, mythology, and folklore. Today, it is often used in fantasy literature and video games. The wyvern in heraldry and folklore is rarely fire-breathing, unlike other dragons