Daffy Duck, of Warner Brothers fame, is probably a Black Swedish - the only difference is that Daffy has white on his neck and a Black Swedish has white on its chest.
They are a hardy, strong duck with good foraging ability. The advantage of the Black Swedish over the Blue Swedish is that the Black Swedish breed true. If you mate a Black Swedish with a Black Swedish, all the progeny will be Black Swedish. As with the Blue Swedish, the Black Swedish was developed in the Pomerania area of Europe. At the time it was part of the Swedish Kingdom but is now the area of northeast Germany and northwest Poland. They were first imported into the USA in the late 1800s.