From A Wiki in the Desert
Cobra Skins are produced periodically in active Serpentariums. The rate at which they are produced is proportional to the number of Cobras living in the Serpentarium.
Horticulture, Obelisk Construction, Technology/Horticulture/2
- 1 used for Sticky Sun Fertilizer
- 2000 needed for Advanced Horticulture research