Consider the opening chapter of Big Fish, “The Day He Was Born” as well as “The Girl in the River” and “In Which He Goes Fishing.” What elements of symbolism or foreshadowing do you see at work?

In Big Fish: A Novel of Mythic Proportions by Daniel Wallace, a son attempts to understand his dying father through the tall tales and myths created about his father’s life. In a collection of connected stories, the author employs magical realism, allusions to Greek mythology, and meditations on the use of storytelling to create the mythic life of Edward Bloom. The chapters you cite reveal key elements in Edward’s characterization.
The opening chapter “The Day He Was Born” begins Edward’s association with water. As Edward's mother goes into labor on a hot, dry summer day, a cloud appears in the sky that is “huge, whale-size.” When Edward is born, it rains and everything changes. The appearance of the cloud brings people outside, gathering them into a community (or an audience) and his parents shift into the roles of Father and Mom. Edward’s birth establishes his role as a rainmaker in both senses of the term: as one who can bring water to a parched landscape, emotions and wonder to lives that have run dry, and money and success to a business.
In traditional symbolism, water can represent qualities of life such as emotions, regeneration, and the subconscious. In the symbolism of the Tarot, Edward is akin to the King of Cups, a court card with fish imagery that contains positive and negative aspects of water, such as creativity and compassion but also manipulation and dishonesty. In the novel, water simultaneously symbolizes Edward’s ability to connect with the mythic realm and his frequent inability to connect with his wife and son, William, in the realm of ordinary life.
In “The Girl in the River,” Edward establishes his aspirations to a heroic, extraordinary life by saving a bathing woman from a poisonous snake. In his telling, William notes that Edward “relied on instinct” to save the woman, instinct being another aspect of water symbolism. As a reward, the woman gives Edward a boon: the place will carry his name. The events of this chapter serve as a test and initiation into Edward’s role as a representative of water and foreshadow the novel’s final scene. But his behavior also indicates where reality and myth, truth and delusion blur in his mind. Because of this blurring and tendency toward delusion, William frequently expresses his exasperation at Edward using stories and jokes as means to avoid being ordinary.
The chapter “In Which He Goes Fishing” establishes Edward’s identification with the role of big fish and his ability to navigate the realm of dream and myth. After a rain and flood, Edward goes out to catch a catfish “as big as a man.” The fish transforms into something like a dolphin (representing a higher stage of awareness) and pulls Edward into a “watery graveyard,” where he is able to see the residents of Ashland who drowned in the flood. Note the neighbor named Homer and how this scene is related in one long, unbroken paragraph, indicating a mythic, inspired state of mind has taken over. Edward’s identification with the big fish and underwater journey foreshadow his eventual transformation at death.