The primary antagonist known for his jealousy in the myth of Hercules is the goddess Hera. Hera's intense envy of Hercules, the offspring of her husband Zeus and a mortal woman, fuels many trials and tribulations in the hero's life. She represents the theme of divine jealousy and the struggles that mortals face due to the actions of gods. Hera's antagonism serves to highlight the complexities of loyalty and resentment within familial and divine relationships in ancient Greek mythology.