I will revise my opinion posted a few minutes ago, as I had on seen a single less in focus photo posted earlier. This is still not and Emperor Goose. Bill size and color suggests Cackling as one of the parents. The white inputs are not so clear. The leg color is odd.
In the field, the back color seemed consistent with Emperor Goose. Unfortunately, I have limited field experience with Emperor Geese, but I do have a bit of experience with odd looking geese in flocks of minima Cacklers, and these odd geese often have splotchy white and black on the neck and head. I wouldn't call the goose at Fernhill a pure Emperor by any means, but it seems plausible it could have some Emperor genes.
Thanks, Steve, for reporting this goose. I was headed to Fernhill anyway, but your post inspired me to look at all the geese until I found it.