Many have questioned the ring around Miz's neck. In anatomy, this is referred to as a 'crop'. It stores rich fat to serve as an energy store.
https://en.wikipedia.org/wiki/Crop_(anatomy)
The crop is particularly pronounced in Canada geese.
in the picture
http://blogg.vm.ntnu.no/naturviten/2018/03/26/norways-new-invaders-canada-goose/?lang=en
please note the pronounced bulge at the base of the neck on the goose at left.