Ghost of Tsushima: Forest Viper

Ghost of Tsushima's Forest Viper is a bow kit for the Longbow. It is one of the cosmetic upgrades that you can buy from merchants.

You can only buy this from a Kamiagata merchant, like the one in the Jogaku Temple.

Acquiring Forest Viper

You can buy it from merchants at the cost of 5 flowers.

Merchants sell not only sword kits, but also bow kits, armor dyes, and hats. 

Visit our Ghost of Tsushima 100% Walkthrough to get more details.