The Hunting Knife is a excellent secondary backup weapon (or even primary if you prefer knives). It is light, durable and has the 'Jaw Stab' attack which can kill a zombie instantly if close enough and timed correctly.
The Hunting Knife can be found in bedrooms, police station storage, gunstores, in fishing storage and in a few other places ingame. It is also a one handed weapon which means you can carry a second bag in the secondary slot (assuming the first bag is on a characters back).
The hunting knife is a single attack weapon, so it is best if used in single combat or if zombies are relatively spread out when attacking.
Since it is also a knife, it can be used similar to the kitchen knife in preparation of food.
Its tree/door damage is negligible. (2 tree, 1 door per attack).