A wattle is a fleshy caruncle hanging from various parts of the head or neck in several groups of birds and mammals. Caruncles in birds include those found on the face, wattles, dewlaps, snoods and earlobes. Wattles are generally paired structures but may occur as a single structure when it is sometimes known as a dewlap. Wattles are frequently organs of sexual dimorphism. In some birds, caruncles are erectile tissue and may or may not have a feather covering.
Wattles are often such a striking morphological characteristic of animals that it features in their common name. For example, the southern and northern cassowary are known as the double-wattled and single-wattled cassowary respectively and there is a breed of domestic pig known as the red wattle.