Most of them are fully imaginary, but some are borrowed from non-Japanese mythologies, like the one in this photo, the Horse-dragon. Coming from the Chinese mythology, the Horse-dragon (Longma in Chinese) has the head of a dragon but without the whiskers, two horns and legs ending in hoofs. Spiritually, the Horse-dragon was considered an omen foretelling a wise ruler...
The sculpture's details are beautiful and I especially like its gaze...
EXIF info:
Nikon D90
Lens: VR 70-300mm F/4.5-5.6G
Focal Length: 300mm
Aperture: F/5.6
Shutter Speed: 1/40s
ISO Sensitivity: ISO 200