Here is a list of mythical creatures beginning with this letter and I am constantly gathering information from each continent and continually updating.
Alkonost (Slavic)
Alkonost makes amazingly beautiful sounds, and those who hear these sounds forget everything they know and want nothing more ever again. She lives in the underworld and lays her eggs on a beach and then rolls them into the sea. When the Alkonost's eggs hatch, a thunderstorm sets in and the sea becomes so rough that it becomes impossible to traverse. She is also the sister of other birds from Slavic mythology, such as Rarog and Stratim.
According to folk tales, at the morning of the Apple Feast of the Saviour day, Sirin flies into the apple orchard and cries sadly. In the afternoon, the Alkonost flies to this place, beginning to rejoice and laugh. Alkonost brushes dew from her wings, granting healing powers to all fruits on the tree she is sitting on.