A ragged-jacket is the name given to a harp

Harp Seal

The harp seal or saddleback seal is a species of earless seal native to the northernmost Atlantic Ocean and adjacent parts of the Arctic Ocean. It now belongs to the monotypic genus Pagophilus. Its scientific name, Pagophilus groenlandicus, means "ice-lover from Greenland", and its synonym, Phoca...

 or grey seal

Grey Seal

The grey seal is found on both shores of the North Atlantic Ocean. It is a large seal of the family Phocidae or "true seals". It is the only species classified in the genus Halichoerus...

 pup when it is undergoing its first moult

Moult

In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...

, and the intermediate stage between a "whitecoat

Whitecoat

A whitecoat is a newborn harp or grey seal with soft, white fur.-From newborn to whitecoat:Newborn seals have yellow fur because of amniotic fluid, and are still wet. When the pup dries, it is called a yellowcoat. The amniotic stain fades and the fur turns white within a few days, and it gets the...

" and a "beater". The moulting begins when the pup is at an age of about 12–14 days, at which time they cease nursing. At this young age, the pups are not yet capable of swimming. The pup stays on the ice for about two weeks before the fur has moulted. It does not feed during this time and therefore loses weight. When the white fur has been completely shed at around four weeks of age, the seal is called a "beater".