Being born with two heads (medical term: polycephaly), is a rare phenomenon that happens naturally in the wild in animals including mammals, insects and reptiles. This occurs as a result of the disruption during development in the organization of the embryonic cells of twins. These individuals often become the focus of local oddity museums or even make National Geographic headlines. For example, the Huron County Museum in Ontario, Canada, has a pair of two-headed calves on display.

Art by Felina Loya.

[Edited by Isabelle McDonald]

References:

Kaufman, M. (2004). The embryology of conjoined twins. Child’s Nervous System, 20(8–9). https://doi.org/10.1007/s00381-004-0985-4

Additional resources to check out:

Mayell, H. (2021, May 4). Life Is Confusing For Two-Headed Snakes. Animals. https://www.nationalgeographic.com/animals/article/news-two-headed-snakes-confusing

A Closer Look: The Science Behind a Two-Headed Calf | Huron County Museum. (n.d.). https://www.huroncountymuseum.ca/a-closer-look-the-science-behind-a-two-headed-calf/