Surfin Bird is one of the three skins released in the first part of the MadJawZ's Shop offer. It could be purchased as part of an item deal in early June 2018.
Surfin Bird could be purchased for $9.99 in a limited time deal that included 16000 coins. It was not available for individual purchase and may not be available for purchase in the future.
Details of this skin may vary depending on location, platform or time.
Note: The first part of the MadJawZ's Shop offer was released again for a limited time in late February to early March 2020. The price and included coins for Surfin Bird remained the same.