The constellation Draco, meaning Dragon, is one of 88 modern constellations. It has been known for centuries, having been listed by Ptolemy as one of the 48 known constellations of the ancient world.
Ancient Egyptians called this constellation Tawaret, after the goddess of the northern sky. She was considered ever-vigilant, since the constellation never set. The fiercely-protective Tawaret’s body was part human, containing other parts from hippos, crocodiles, and lionesses.
To the Greeks, the constellation resembled a dragon, thus the name Draco. In one myth, Draco (as Ladon, the hundred-headed dragon who guarded the golden apples of the Hesperides) was killed by Heracles. The goddess Hera lifted Draco, placing him in the sky.
A different Greek legend claims that Draco was killed by Cadmus, who went on to found the city of Thebes. Another story claims that Draco was the dragon who guarded the Golden Fleece, subsequently killed by Jason. Since this circumpolar constellation never set, it was visible at all times. Perhaps this is why it was so commonly used in mythology.