Jonathan Faust was the founder and the first leader of the Vipers.
When Vault 15 opened its door during the spring of 2141, Jonathan Faust left the vault with a group of about 200 people in search of another place to live in. While traveling, Faust was knocked into a hole filled with deadly pit vipers. He was grazed by several fangs, but the poison was not enough to kill him. The poison was enough to make him hallucinate, making him see a vision of a giant viper, and knew that his destiny was bound to it. The Vipers were therefore born.
During a minor conflict with the Brotherhood of Steel around the early 2150s, one of the Vipers used a toxic arrow to kill one of the Maxson clan. This enraged the Brothers, and the remaining Elders ordered for every last Viper to be scourged from the blasted Earth beneath them. Jonathan Faust was killed while defending the main Viper camp and his son, Asp Faust, became the leader of the Vipers shortly afterwards.
Jonathan Faust is only mentioned in Fallout.