The Dunk was a skin added to Agar.io with the Sports Skins update. Unlike the other skins, Dunk had to be purchased in a Coin Deal.
Note: Dunk was released again for a limited time under the The Collector's offer in July 2017 and then in July 2024. For these releases, Burger Face, Dunk and 16000 coins could be purchased for $9.99.