Crested Khaki Campbell Ducks have solid brown or khaki colored plumage and are characterized by having a crest that are globular in form and relatively large. Khaki Campbell Ducks have been bred to be one of the most prolific layers of all breeds of poultry. They are an active, moderately streamlined bird that has been bred without concentration on extreme characteristics. Since there is a lethal gene involved in producing crested ducks, special mating considerations must be made.