Big Horn is one of the two skins released in the second part of the Creepy Christmas offer. It could be purchased as part of an item deal for a limited time in late December 2020.
Big Horn could be purchased for $9.99 in a deal that included a package of 13500 coins. It could also be purchased for $19.99 in the "Best Deal!" which included 22000 coins, 2500 DNA, two 3x XP Boosts (1 Hour), two 3x Mass Boosts (1 Hour) and the Wicked Frosty skin. Big Horn was not available for individual purchase and may not be available for purchase in the future.
Details of this skin can vary depending on location, platform or time.