The Necromancer requires a ready supply of mortal remains as subjects for their dark magic. Keeping fresh (or not so fresh) body parts can be difficult however, especially in large quantities. These items are essential for any serious practitioner of the Necromantic arts.
Although you could just stuff a body in any old sack the Body Bag is a vastly superior choice. This huge leather bag has a thick double lining and is waterproof. It can shut air-tight when drawn closed. A Body Bag can hold up to ten hit dice worth of body parts and weighs 1ENR if empty ( it can fold up fairly small when not in use). If in use the Body Bag weighs 1ENR + 1ENR per hit dice worth of body parts contained within. A Body Bag can be used by non-necromancers as well as a means of transporting the body parts of exotic creatures to market, or even to safely transport the remains of a fallen comrade. A Body Bag costs 10gp.
These alchemical potions help greatly to stave off the effects of rot and decay. If a single dose if poured into a Body Bag and left overnight all the remains inside the bag will stay "fresh". If a Body Bag receives daily applications of Preservative Agents and is kept in a cold and vermin-free environment it will continue to preserve the remains nearly indefinitely. The alchemical ingredients required to make Preservative Agents are expensive and rare however, thus each dose costs 5gp.
These vile little creatures are of invaluable help to Necromancers who prefer to work with skeletal remains. Each Scarab is only slightly larger than a coin and they are typically sold in small colony groups of a few dozen individuals. A colony of Flesh Scarabs comes in a small sealed iron box which contains a small quantity of sand. If the open box is placed inside a Body Bag which contains "fleshy" remains and left overnight by morning the bones will be stripped nearly clean of flesh and the scarabs will have retreated back into their sandy home. A colony of Scarabs which are given a steady supply of flesh to eat will be able to reproduce and replenish their numbers indefinitely but it is impossible to breed additional colonies. Each colony of Flesh Scarabs must be imported from distant lands and thus each box costs 50gp, The iron box they are housed in weighs 1ENR.
A Peddler's Bag is a small cloth bag which contains simple supplies of the sort usually used by peddlers to mend shabby clothes. Each bag usually contains a random assortment of soiled rags, strips of leather, wooden sticks, nails, small twisted bits of metal, pins, needles, string and twine. Each bag weighs 1ENR and contains 20 uses. You could scrounge up the materials that make a Peddler's Bag by paying any shopkeeper 3 copper pieces for the privilege of searching through their waste-bin.
( Note: Many Necromancer spells such as "Create Skeletal Wretch" require 1d6 uses from a Peddler's Bag, as well as many of the spells used by Animators.)