Fresh animal skin
An animal carcass can be skinned using the hideworking skill ( + ) to receive a fresh animal skin. The skin will then need to be cleaned and either tanned or cured for preservation so it won't rot. Tanning will turn the skin into leather or fur depending on the animal it is from. More information about tanning can be found on the Hideworking (Skill) article.
Skinning needs to be done before butchering, as butchering will destroy the skin.