Ophiotaurus was a monster in Greek mythology. It had the front of a bull with front legs, but lower body was a serpentine tail. Artistic impressions may vary. Sometimes Ophiotaurus is depicted as an enormous snake with a bull's head.
Ophiotaurus was a monster born of Gaia, though in some sources it was a creature that came into being from chaos along with Gaia and Ouranos. It had an important role in War of the Heavens. While Ophiotaurus hadn't sided with either gods or titans , the Fates (Moirai) made a potent prophecy at the moment of Ophiotaurus's birth. If someone was to slay it and burn it's entrails in flame, it would ensure victory against the gods.
Gods needed to make sure the creature would never be found. The goddess Styx (also as a personification of an underworld river) imprisoned the creature. However, an ally of the titans finds Ophiotaurus and slays it. Before innards are set aflame, eagles sent by Zeus pick them up and carry them high up into the sky, so high that they become the Taurus constellation.