Final answer:
Prometheus offended Zeus by tricking him into accepting poor quality sacrifices and by stealing fire to give to mankind, both of which benefitted humans and angered Zeus. Additionally, Prometheus's involvement in the creation of mankind may also have played a role in the discord.
Step-by-step explanation:
Prometheus, the Titan in Greek mythology, is known for his offenses against Zeus for the sake of mankind, which include several significant acts. First, he tricked Zeus in the matter of sacrifices, where he created two piles of meat, one covered with a fat layer without meat and another with the good meat hidden inside an ox's stomach, which was considered undesirable. Zeus chose the fat-covered pile, thus decreeing that humans would keep the meat for themselves and burn only the bones and fat as an offering to the gods. Secondly, Prometheus stole fire from the gods and gave it to humanity, which enabled human progress and civilization. This act greatly offended Zeus because fire was meant to be the prerogative of the gods alone, and its possession significantly benefited humans. As a punishment for this audacity, Zeus had Prometheus chained to a rock where an eagle would eat his liver every day, which would then regrow to be eaten again the next day. Lastly, there's a belief that Prometheus took part in the creation of man and thus implied his hand in humanity's protected status, which may also have caused tension between him and Zeus who had less regard for the mortal beings compared to Prometheus.