Embalm

An embalm spell enables the caster to protect a corpse (or a harvested part thereof) against the natural forces of decay and dissolution, until some later time when it is needed for a spell. If a embalmed cadaver is later animated as a zombie, golem, or other form of animated undead, the creature gains +2 hit points per hit die (8 hp/HD maximum) because of the greater strength and resiliency imparted by the spell to the dead tissue. It has no beneficial effect if cast on skeletal remains or on previously animated undead.
Thus preserved, a corpse permanently retains the same odor and appearance it had at the time of casting. Embalm does not reverse the effects of putrefaction, but it does prevent any further decay of an individual's physical remains. Unlike more powerful spells, embalm does not facilitate subsequent resurrection of a corpse.

adapted from 2E The Complete Book of Necromancers By Steve Kurtz