Taharka is a boss from Final Fantasy IX. It is fought in Ipsen's Castle. The party comes to Ipsen's Castle to find a way to break the seal to get to Terra. Four mirrors in Ipsen's Castle help the party in doing this. Taharka is the guardian of the mirrors and will fight the party to return them.
During the fight, Taharka will compact into a ball, greatly increasing its defense against physical attacks. This makes magic very useful, so be sure to bring either Vivi or Quina to the battle. For an easy win, inflict Heat on Taharka using Quina's Mustard Bomb or equip the Add Status ability with Steiner's Flame Saber. It will instantly kill itself on its next turn. Silence works wonders here, also.
In the same manner as the guardians of the shrines are weaker versions of the Chaos Guardians fought in Memoria, Taharka could be considered a weaker incarnation of Deathguise, who is also fought in Memoria. The two look similar and share the gimmick of curling up and opening to change their attack patterns.