This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Zhar-Ptitsa (Slavic)
In Slavic mythology and folklore, the Firebird (Ukrainian:, zhar-ptytsia; Bulgarian: Zhar-ptitsa) is a magical and prophetic glowing or burning bird from a faraway land which is both a blessing and a harbinger of doom to its captor.
The Firebird is described in one of the texts collected by Alexander Afanasyev as having "golden feathers, while its eyes were like unto oriental crystal".
Other sources portray a large bird with majestic plumage that glows brightly emitting red, orange, and yellow light, like a bonfire that is just past the turbulent flame. The feathers do not cease glowing if removed, and one feather can light a large room if not concealed. The form of the Firebird is usually that of a smallish fire-colored falcon, complete with a crest on its head and tail feathers with glowing "eyes".