Crested chickens

old engraving of a hen with a crest of feathers
old engraving of a cock with a crest of feathers
Ulisse Aldrovandi, illustrations of crested hen and cock, from the Ornithologiae tomus alter of 1600
Detail of Kippen en eenden by Melchior d'Hondecoeter, circa 1680

Crested chickens are a group of ornamental chicken breeds characterised by a tuft or crest of upward-pointing feathers on the head.