Cat Fangs in Green Hell can be obtained by harvesting them from dead Jaguars or Pumas. Of course, dealing with either of these animals can lead to your death if you are unprepared. Both cats will become highly aggressive if you get too close, so be careful when you see or hear them.
The best way to take down a Jaguar or Puma is to throw a spear at their head. Bows and arrows will probably be your best follow-up weapon if you do not have a spear. You also could use a closer weapon for melee, but we do not recommend getting close to either animal.
Once you have harvested the Cat Fangs, Empty Mold and Melted Iron Ore to make Cat Fangs Mold. Place that mold in the Forge to bake it and get Metal Cat Fangs. Note that you will need to have read all of the Craftsmen Legend Stories before you can do this.