The Primal Stink Bow is a weapon that was added in Patch 16.00. It comes in Epic and Legendary variants. It must be charged in order to hit ranged attacks. It can be obtained by crafting Using a Stink Sack or 3 Stink Fish.
It has a headshot multiplier of x2. On impact, it spawns a stink effect (similar to a Stink Bomb).