What is the flap of skin which hangs from neck called?

The flap of skin that hangs from the neck is called the " dewlap" .

It's most commonly seen in certain animals, like:

* Cattle: Their dewlaps are prominent and often used for identification purposes.

* Dogs: Some breeds, like the Shar-Pei, have dewlaps.

* Goats: Dewlaps are also common in goats, especially in some breeds.

* Lizards: Some lizard species have dewlaps that they use for display and communication.

While humans do not have dewlaps, they sometimes have a loose fold of skin under the chin called a "double chin" due to fat deposits in the neck.