The Beastmode skin is an Epic Fortnite outfit. Beastmode was available via the Item Shop for 1500 V-Bucks and you can buy it from Fortnite Item Shop when it will listed.
Fortnite Beastmode Outfit Details
Gassed up and ready to roar.
Fortnite Beastmode Outfit PNG Images
Here is the PNG images of Beastmode below!