Wendigo is one of the six skins released under the Moonlight Festival offer. It could be purchased for a limited time as part of an item deal in late October 2017.
Wendigo could be purchased for $4.99 in a deal that included 3250 coins. It could also be purchased for $19.99 in a deal that included the Night Hunter skin and either 50000 coins (Browser) or 1800 DNA (Mobile). It was not available for individual purchase and may not be available for purchase in the future.
Details of this offer may vary depending on location and platform.
Note: Wendigo could be purchased again as part of The Dark Collector offer in early August 2018 and then in early August 2019. Wendigo, Wicked Clown and 16000 coins could be purchased for $4.99 in this recurring limited time offer.