Mangy Goose?

So this one is from my birthday as well but it deserves a post of it's own. During my birthday walk in the park with Linda we stopped for a break at a little pond were we saw this fellow.

Linda sort of knows all kinds of birds from a previous life in which she was an avid bird watcher or something like that. Any way she had no idea what this was. It was hanging out with a bunch of geese but other than the size didn't really look like any of the other geese. So what is it? We are thinking maybe it's just a goose with the mange. Linda tried to look it up on line with no luck.

Anyone know what kind of bird this is or is it just a mangy goose?