Karst was cast out from the tribe for five years after he was caught exploring metal ruins, a practice forbidden by Nora law. After his years as an outcast were finished, Karst returned to his home in Mother's Heart only to discover that everyone he knew had moved on. Seeing that there was nothing left for him in his old village, Karst chose to live in a home in the woods that he had grown accustomed to during his life as an outcast.
- His name refers to Karst topography, which is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum and is characterized by underground drainage systems with sinkholes and caves.
- He is possibly related to Teb and the Nora Keeper, as they share the same familial face paint.
- Karst is the only deceased merchant in the game.
|High Matriarchs||Jezza - Lansra - Teersa|
|Tribe Members||Aloy - Arana - Bast - Den - Dral - Dran - Enara - Ferl - Fia - Grist - Jarg - Jarm - Jun - Karst - Lut - Marea - Muns - Nakoa - Olara - Orn - Resh - Solai - Sona - Taim - Teb - Thok - Vala - Varl - Yan|
|Outcasts||Brom - Cren - Grata - Jom - Kam - Kurnst - Nora Keeper - Rost - Yun|