The White Bull
The story is based on the Greek mythological tale of Europa and the bull, where the white bull is the king of the Greek gods, Zeus, in disguise. Zeus, the sky and thunder god of the Olympic pantheon, often wore a disguise when romantically pursuing mortal women, so as to avoid the eye of his wife and sister, Hera.
Echo (mythology)
In Greek mythology, Echo (; , "Ēkhō", "echo", from ἦχος ("ēchos"), "sound") was an Oread who resided on Mount Cithaeron. Zeus loved consorting with beautiful nymphs and often visited them on Earth. Eventually, Zeus's wife, Hera, became suspicious, and came from Mt. Olympus in an attempt to catch Zeus with the nymphs. Echo, by trying to protect Zeus (Zeus ordered her to protect him), endured Hera's wrath, and Hera made her only able to speak the last words spoken to her. So when Echo met Narcissus and fell in love with him, she was unable to tell him how she felt and was forced to watch him as he fell in love with himself.