Details on Amiibo skins and how the Yarn Yoshi Amiibo came to be.
http://www.nintendoworldreport.com/news/40463/yoshis-woolly-world-details-and-release-date-for-north-america
Yoshi's Woolly World is now slated for release on October 16 in North America.
The game's corresponding Yarn Yoshi Amiibo actually got its origin when a staff member created one on a whim. The Amiibo was so beloved by game staff that they then began to make plans to actually produce the Yarn Yoshi Amiibo for release.
Nintendo also has re-confirmed that various Amiibo will be able to give Yoshi various looks, for example, Mario or Samus.