The Fire Clan General was the leader of the Fire Clan in the war against the Ice Clan, led by Lucia the 43rd.
After attacking the TARDIS causing it to crash down onto the planet, he captured the Doctor believing him to be an Ice spy and imprisoned him with Zarr. After the two escaped he was set to kill the two before noticing the footsteps of an army and went to attack the Ice Clan by unleashing his secret weapon, the Doombringer and the volcano to wipe out all Ice lifeforms.
However the Beginner put an end to his scheme, riding the Doombringer to absorb the energy of the volcano and unleashing the power onto the Fire Clan base, destroying them all. (When Worlds Collide)