The Eagle and Crabs in the Greek mythology - presented by Jack the Lizard More images and stories are at Jack the Lizard Wonder World http://www.animal-dino.com
The story is from that of Prometheus or Tityus.
Prometheus is punished for his theft. He stole the fire from Gods and gave it to human. Zeus, king of the Gods, got angry furiously and chained Prometheus to mount Caucasus. On the mountain Prometheus is tormented by the giant eagle which eats the liver of Prometheus day after day. The liver grows back during the night because Prometheus is immortal. Although the punishment seems to last forever, Prometheus is rescued by Heracles who shot the giant eagle.
The symbols of Zeus are bull, oak and eagle. The crabs might represent the arrival of Heracles.
This illustration is based on the drawing of Michelangelo Buonarroti (1475-1564).