The mallard duck, also known as the big green head and the big red-legged duck, is an animal of the genus Duck in the family Duckidae of the order Geese, also known as the big mallard duck. It is listed on the IUCN Red List of Threatened Species and is a second-class protected animal.

The mallard male has a green head and neck with a brilliant metallic luster. There is a white collar at the base of the neck. The upper back and both shoulders are brown. Every year, mallard ducks will fly to the south for the winter, often gathering a large group.