This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Wyrm – English)
Wyrms (alternatively wurms, worms or orms) are serpentine dragons, normally of European origins. The word (derived from the Norse 'ormr') used to mean all dragons (or all dragons known in Europe/European dragons), but in modern use it is reserved for dragons with 'wormlike' qualities: a long body shape which is either legless or with small legs.
Wyrms in Britain include the Lambton Worm and the Laidly Worm of Bambrough, as well as many more wyrm legends that go by other names: in Sussex, deep pools in the ground are inhabited by wyrms called knuckers. In Wales, the wyrms are called anfanc, and in Scotland they may be called beithir.