You can get the Red Dead Redemption II Bison Horn Talisman starting Chapter 2, but in order to craft it, you need three special materials.
This specific item affects Arthur’s Stamina Core.
Bison Horn Talisman Materials:
1x Abalone Shell Fragment – This unique item is inside a house in Rhodes. The said house is north from the sheriff’s office. You can see the exact location marked on our RDR2 Unique Items locations map. Check position 2.
1x Silver Earring – The Silver Earring is a random loot drop. As with most valuables you can obtain it through robbing. Your best chance to get one is by robbing civilians on trains.
How to Craft the Bison Talisman:
When you get all the materials you need, travel to a Fence and pay the shopkeeper who will craft the talisman for you.
How to Use the Bison Horn Talisman:
Keep the RDR2 Bison Horn Talisman in your inventory to benefit from it. This unique talisman will decrease the draining speed of your Stamina Core by 10%.