Sinister necromantic magic infuses the remains of the dead, causing them to rise as zombies that do their creator's bidding without fear or hesitation. They move with a jerky, uneven gait, clad in the moldering apparel they wore when put to rest, and carrying the stench of decay.
Most zombies are made from humanoid remains, though the flesh and bones of any formerly living creature can be imbued with a semblance of life. Necromantic magic, usually from spells, animates a zombie. Some zombies rise spontaneously when dark magic saturates an area. Once turned into a zombie, a creature can't be restored to life except by powerful magic, such as a resurrection spell.
A zombie retains no vestiges of its former self, its mind devoid of thought and imagination. A zombie left without orders simply stands in place and rots unless something comes along that it can kill. The magic animating a zombie imbues it with evil, so left without purpose, it attacks any living creature it encounters.