Shadows. A necromancer can readily summon these evil spirits from the Negative Material Plane once at the 9th level of experience (see summon shadow). These creatures answer a necromancer's summons willingly, for it provides an easy opportunity for them to feast on life force. Once the summoning expires, these creatures usually return to the Negative Material Plane very quickly. They do have free will, however, and if properly approached, may even enter the wizard's service, assuming that they will be provided with enough fresh life force to temporarily ensure their loyalty. Highly chaotic, violently hungry, and unpredictable, shadows rarely stay attached to a living master for long, especially if the wizard has valuable living allies. They can sometimes be found in the permanent retinue of a lich.