This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Zmiy (Slavic)
The dragon in Russian folk fiction may be female, in which case she is called zmeya. The tendency is for the prose folktale versions to have male dragons, and the byliny poetry to have the females. This will affect the behavior of the dragons. For instance, only the male dragons will capture or captivate a princess or a maiden as a love interest.
A zmei may be beast-like or human-like, sometimes wooing women, but often plays the role of chief antagonist in Russian literature. In the Balkans, the zmei type is overall regarded as benevolent, as opposed to malevolent dragons known variously as lamia, ala or hala, or azdaja.