Hydrus was a constellation noticed in 1595.
Draco was the first law scribe of ancient Greece known for harsh punishments-- note the phrase 'draconian law'. Because he felt minor crimes gave way to major crimes, the punishment for minor crimes was often the death penalty.

In Greek mythology the Hydra was a serpent link creature that dwelt in the water. Its breath was poison and when one of its several heads was severed, two would grow back in replacement. The Hydra was destroyed by Hercules. Some legends say the stumps were burned so more heads wouldnt regrow; other legends say Hercules used the hydra's own poison blood to stop the regrowth.