In ancient Greek religion, Nemesis (Ancient Greek: Νέμεσις), is the goddess who takes vengeance against those who show hubris (arrogance before the gods).
Divine retribution is a major theme in the Hellenic world view. It is the unifying theme of the tragedies of Sophocles and many other literary works.[1][2]
She carried a measuring rod (a tally stick), a bridle, scales, a sword, and a scourge (whip), and she rides in a chariot drawn by griffins.
Nemesis often is seen with another goddess named Aidos. Aidos is the goddess of shame. She is similar to Nemesis.[3]
The Ancient Greek made different meanings for what they called "justice":
In works of fiction the hero's nemesis is usually the villain and the hardest antagonist for the hero to defeat.
Media related to Nemesis at Wikimedia Commons