Haha, apparently yes, didn't look up, "in a dairy cow, each ovary is approximately 1.5 inches (38.1 mm) long and 3/4 inch (19.05 mm) in diameter" [1] with the oocytes around 115 micrometers, whereas a large hen would produce eggs around 2.44 in (62 mm) length and 1.69 in (43 mm) diameter [2].
"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.
[1] https://www.thecattlesite.com/articles/1031/anatomy-of-the-c...
[2] https://brinsea.co.uk/latest/resource-centre/egg-sizes