Unknown white water bird

Hi Laurius, and welcome to the forum!

I would think ,this is a" Muscovy Duck" , as it’s pretty easy to tell. The most obvious character of a muscovy is the red facial skin. If your duck has a red face, it’s probably a Muscovy Duck. This red skin can be quite bumpy, exaggerated, and frankly, gross, with a knob on top of the bill and lumps all over. If you see that, it’s a slam dunk Muscovy Duck. The wild type plumage of muscovy is all black, glossy greenish on the back, and with large white wing patches. But, because of our fondness for white, domestic muscovies can be pure white, all black, or any degree of pied black-and-white.

I hope that helps,happy birding, M-L