The head of a puffin is as large as a golf-ball. The eyes are placed closer to the front of the head. Its most unique characteristic is its bill. Puffins have a triangular, colorful bill that is blunt and comes to a curved point. Puffins have dark orange feet, that are webbed in a palmate formation.
Puffins have no hind toe.
Horned puffins have evolutionarily adapted to predation by way of camouflage. When puffins are swimming, to predators above them they blend in with the bottom of the sea as a result of their black upperparts. Any predators below have a hard time seeing them because their white stomachs look like a reflection of the sunlight. There is sexual dimorphism in bill color and size. The female's bill is not as bright as the males, the male's bill is also bigger than the female's.