"Although [whale sharks] produce eggs, they don't lay them. Instead, the young hatch while still in the female's body and are born as miniature adults. This is known as ovoviviparity." [1] The More You Know.
So, technically, the largest egg, as in laid egg, is the ostrich's (around 6 inches), although, the largest egg in relation to body size belongs to the kiwi (25%) [2]. For more eggs facts press 1.
