In Greek mythology, Sisyphus was king of Corinth.
Sisyphus was distinguished by great wisdom and contributed greatly to the expansion of Corinth.
However, this made him arrogant and made him believe he was smarter than the gods. He angered the gods with his hubris.
One day he watched from his tower as Zeus, in the form of an eagle, kidnapped the nymph Aegina, daughter of the river god Asopos. Sisyphus waited for the opportunity to use this knowledge.
Asopus was looking for his daughter until he came across Sisyphus. Asopus asked the stubborn King Sisyphus the name of who had kidnapped his daughter Aegina.
Sisyphus named Zeus as the kidnapper and in return Asopos built a water spring on the Acrocorinth.
To his chagrin, Zeus had to give Aegina back; she gave birth to Aikos, who later became king of the Myrmidons and the progenitor of the Aiacids.
Enraged by Sisyphus" interference, Zeus sent Thanatos, the god of death, to escort Sisyphus to the underworld.
But Sisyphus was able to outwit and imprison Thanatos.
From then on no one died anymore, which angered Hades (because no new dead came to the underworld) and Ares (because wars without dead people made no sense to him).
Ares freed Thanatos and Sisyphus had to follow him into the underworld.
But Sisyphus left instructions to his wife Merope not to bury him. Sisyphus was able to persuade Hades to let him return to earth so that he could ask his wife to give him a proper burial.
Back home, the cunning man enjoyed life at his wife"s side and mocked the god of the underworld.
But suddenly Thanatos appeared in front of him and took him by force to the realm of the dead. Sisyphus"s eternal punishment in the underworld was to roll a boulder up a steep slope. However, the stone always slipped away from him just before reaching the summit and he had to start again and again.
Today, a task that is never completed despite great effort is called Sisyphean work.

Using Hero Forge I created Sisyphus and Thanatos as anthropomorphic animals.
Sisyphus as a fox (in classic fairy tales, the fox is characterized as a particularly clever, cunning and sometimes deceitful animal) and Thanatos as a raven (ravens and crows often appear in fairy tales as symbols of death or separation).
The fox Sisyphus shows no fear, but grins so confidently.