Final answer:
In Greek mythology, Sisyphus was punished by having to push an immense rock uphill for eternity, as a punishment for his evil actions during his life.
Step-by-step explanation:
The person who had to push a huge rock uphill as punishment was Sisyphus, a character from Greek mythology. Sisyphus was a king known for his trickery and deceitfulness. His punishment in the afterlife, as devised by the gods, was to eternally roll a massive stone up a steep hill, only for it to roll back down each time it neared the top. This task was meant to be futile and neverending, symbolizing an extreme form of punishment for his lifetime of misdeeds.