Sad is one of the five skins released under the Skins part of the Agar.io Birthday offer. It was available for individual purchase with game coins in mid July 2017.
Sad could be purchased in the Skins Shop under the ‘Birthday Special’ tab for 2900 coins. This skin was available for a limited time and may not be available for purchase in the future.
Details of this offer can vary depending on location, platform or time.