According to the Livestock Conservancy:

“The Sebastopol is readily identified by its feathers: long, soft-quilled, curling feathers drape elegantly from its wings, body, and tail. This modification in plumage is an example of breeding for a specific trait….This attractive, friendly breed has a quiet and pleasant disposition, are excellent foragers, fatten easily, and they make gentle pets as they are more on the shy side than aggressive like some other goose breeds. They are a dual-purpose and ornamental breed and can be used to keep the grass short where they are raised. “

Read more here:

https://livestockconservancy.org/heritage-breeds/heritage-breeds-list/sebastopol-goose /