Looks like a muscovy and a female mallard...
Didn't know muscovy. Looking up, I saw a number of color patterns but most seemed to have the red caruncle around their beak. Can it be otherwise at times of life or year? Definitely an odd duck in the true sense of the phrase.
Okay, maybe not muscovy, but a mallard mixed with domestic? https://www.birds.cornell.edu/crows/domducks.htm
Maybe that's it. The fellow who owns it must know. Beth spoke with him the other day. I could use it as an opportunity to say hello/inquire. He has 4 'free-roaming' ducks - which seems a death sentence for one or more given what's been seen in the area over the years. I think most dogs would do harm. Ours is still too young, not mean, a bit timid, a lot curious