The Mandrake is an enemy in the DS version from Final Fantasy III, fought on the areas of the World Map around Canaan and Vikings' Cove. The NES version of this enemy does not appear anywhere. As a plant enemy, Mandrakes are weak to Fire.
Mandrake is another name for the mandragora genus of plants. Mandragora is a plant belonging to the nightshade family. According to legends surrounding witchcraft, when mandragoras (Mandrake plants) are uprooted, they emit a piercing scream which kills all who hear it.