A zombie is an undead creature usually created by the re-animation of a corpse. Unlike animated skeletons, zombies still retain some flesh on their bodies, and give off a horrid, rank smell. They are almost mindless, but can be given simple commands, such as "kill anyone who opens the treasure chest." Virtually any solid creature can be turned into a zombie; in addition to humanoids, troglodytes, minotaurs, ogres, and even beholders can be turned into zombies.
Basically, a zombie is the corpse of a creature which had been animated by someone who can manipulate negative energy, such as a cleric. For example, a cleric will be able to use negative energy on a corpse and make it move its body, arms, legs, etc. Zombies can also rise spontaneously if an area was saturated with necromantic magic.
Zombies drag their feet and so do not leave clear prints.