When playing Taros there is the possibility of playing with an army of undead hordes. The zombie is the most basic undead unit, built very fast and costing little mana. This allows the player to field a horde of zombies early on to swarm the enemy on small maps as the zombie moves slowly. This can be solved somewhat with the use of ghost ships.
Tactics involving zombies (being a so expendable) usually include a unit able to cause area-of-effect attack such as the Lich (who cause less damage to undead units) or Taros magicians that benefit from the screen provided by a zombie horde to use their "rain" attack spells or mind control before retreating.