Mecha Destroyer is one of the nine skins released in the multi-part Cap'n Joe's Shop offer. It could be purchased as part of this item deal for a limited time in mid July 2018.
Mecha Destroyer could be purchased for $14.99 in the "Best Deal!" which included 25000 coins, 1200 DNA and the Mecha Parrot skin. This skin 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 part of the Cap'n Joe's Shop offer with the Mecha Destroyer skin was released again for a limited time in late July 2019. This time the Best Deal was lowered to $9.99 with the included coins being reduced to 30000. The package of DNA was no longer included.