Sirens are a type of salamander, and this newly discovered species in Florida is one of the largest species to be found in North America. The frills on either side of their head are actually external gills, which they use to pull oxygen from water.
Bittel, Jason. “New Species of Giant Salamander Discovered in Florida.” Animals, National Geographic, 5 Dec. 2018, www.nationalgeographic.com/animals/2018/12/new-species-of-giant-salamander-siren-discovered-florida/.