Thick Fur is an item from the Reign of Giants DLC. It is dropped by the Bearger. Its only purpose is to be used to craft the Hibearnation Vest and the Insulated Pack.
In Don't Starve Together, 3 Thick Fur can be crafted from 90 Fur Tufts. It is under the Refine Tab.
Meat Effigy • Prestihatitator • Shadow Manipulator • Pan Flute • One-man Band • Night Light • Night Armor • Dark Sword • Bat Bat • Life Giving Amulet • Chilled Amulet • Nightmare Amulet • Fire Staff • Ice Staff • Telelocator Staff • Telelocator Focus • Belt of Hunger(Old Bell ) (Ocuvigil • Abigail's Flower • Moondial • The Lazy Deserter )