One of the more popular myths to come out of Ancient Greece is that of the hydra. This many headed serpent was killed by Hercules, according to Greek mythology. This beast might not be simply a legend, however. Bicephalic snakes are not common, but they do exist. These snakes have two heads, complete with two brains that oftentimes will be in conflict against each other. These anomalies have been captured and are sometimes put on display. For example, Thelma and Louise, a two-headed corn snake, was kept at the San Diego Zoo for many years. There have been reports of two-headed snakes in other variations, including a California Kingsnake that is now on display at a zoo in the Ukraine. These novelties seem like fairytale creatures, but they are actual living abnormalities.
These snakes do not last long in the wild as one head will sometimes attack the other when they are hungry. But under human care, these snakes can be satiated and kept well for long periods of time. Scientists believe that this anomaly occurs for the same reason that conjoined twins occur in humans—a connection between two embryonic disks. This happens in about 1 out of every 100,000 births in humans, and roughly half of these sets of twins are stillborn.
The hydra might just be a mythical creature, but it was probably a bicephalic snake that inspired the creation of this myth. As the years progressed the story may have been exaggerated and embellished, but at the heart of the myth, there is a kernel of truth.
