Australian Shelduck Tadorna tadornoides
So far I've only seen this species in captivity. Escaped birds occasionally turn up in the wild in Europe but beware hybrid Shelducks which may superficially resemble this species (including some Ruddy Shelduck x Common Shelduck hybrids).
captive Australian Shelduck, Grange-over-Sands (Cumbria, UK), 28th December 2011