Zhang Heng stood at 7 feet, had triangular eyes, yellow whiskers, red hair, and crimson eyes. He had the ability to swim in the water like a fish, leaping out of the water from wave to wave and even harsh weather conditions could not stop him. Thus, he was nicknamed the 'Boatman'.
Zhang lived at the foot of Mt Gushan. He was Zhang Shun's elder brother, Li Jun's sworn brother. The Zhang brothers did some illegal trading on the river for a living. Zhang Heng gambled frequently, and lost a huge sum of money. Then, he became a ferryman, but was in fact a pirate.