Earthbender captain

This captain is a vengeful man who wants the Fire Nation to pay for what they've done to the world. He fought against Iroh and the Fire Nation army during the 600-day siege of Ba Sing Se. He doesn't consider Iroh as anything but an Earth Kingdom enemy. He will do anything to protect his nation and especially the Earth Kingdom capital of Ba Sing Se.

History
In "Winter Solstice Part 1: The Spirit World", he and his unit of Earthbending soldiers discover Iroh bathing, and capture him. While he is captured, Iroh attempts to convince the Captain that he is nothing more than a harmless old man by acting weak. He pretends to fall asleep in his saddle, leaving behind his slipper as part of a trail for Zuko to find. He makes an escape attempt when he complains of his handcuffs being too loose. When one of the soldiers goes to tighten it, Iroh heats it up to scalding temperatures, burning the soldier's hand.

Iroh rolls off the Ostrich Horse, and down a mountainside. The Earthbender Captain and his soldiers catch up to him however, and recapture him through the use of Earthbending. The Captain decides that it is too dangerous to transport him to Ba Sing Se as he is. He plans to crush his hands as a precaution. However, before he can do this, Iroh is saved by Zuko, and the two of them fight against the Captain and his soldiers. After the Earth Kingdom warriors are defeated, Zuko and Iroh leave to continue their quest. The Earthbender Captain is never seen again.