Cupid on a Sea Monster draws heavily from mythology. One of Bouguereau's distinctive style, for which he is famous, is his depiction of themes from Pagan and Christian mythology.

He was heavily influenced by Raphael, the great Renaissance artists, whose styles and underlying themes he emulates. Another distinctive style that defines him is his skilful and elegant use of the naked human body as an art form.

True to style, "Cupid on a Sea Monster" draws both characters and themes from ancient Greek and Roman mythology. In the painting, a cupid rests on a sea monster dragon, who floats in placid waters. The image of a ferocious sea monster and the cupid makes for an interesting contrast.

In Greek mythology, Cupid is the god of erotic love, desire, affection, and attraction, all concepts Bouguereau has held dear throughout his life.

The sea monster is characteristically depicted as a frightening creature, with the head of a horse and the body of a fish. The painting epitomises refinement, a fine taste, and a respect for tradition, typical of Bouguereau's works.

Cupid on a Sea Monster was executed in 1857, when Bouguereau was already well-established as an artist, and at the peak of his powers. In his heyday, the academic art community regarded him as among the greatest living painters in the world.

He had a good rapport with art dealers and clients alike, and he was a regular at the Paris Saloon art exhibition.

Most of his paintings depict the in-demand themes and style of his patrons. His paintings always sold for high prices, and he was a favourite of American millionaires, who developed a special liking for his paintings.

In all, Bouguereau executed 822 paintings, for which he received widespread fame, popularity, and honours, not only in France, but also in Netherlands, Spain, Belgium, and the USA.