Fang is collected by killing and harvesting Wolfs or as a passive income from a Wolf Pen. Its a essential material used to craft a Boar Head Statue, War Rhino Armour, War Elephant Armour and different Powder to polish items.
The slower method to get it is to kill and harvest Wolfs. The probability of obtaining Fang from harvesting are very low, but the chance is there.
The much more effective way to get Fang is by building a Wolf Pen. Catch and breed Wolfs to get a permanent passive income of Fang and other resources if you feed them. Once you hit level 33 you can unlock it. Press “P” to open “Crafting & Recipes” and unlock “Animal Pen”.
Check out this guide to learn more about Pens and how to catch and breed Wolfs.
The more animals are in the Pen, the more ressources you get. You can build Pens for every animal in the game except of horses, elephants and rhinos.