Haku was a young man with an androgynous appearance and was even viewed as being beautiful by Naruto, who exclaimed that he was "prettier than Sakura", even after he informed him that he was male. He had long black hair, pale skin and large, dark-brown eyes, a slender frame, and was also quite short for his age. Haku's normal shinobi outfit consisted of the standard Hidden Mist Village pinstriped outfit which stopped at his knees. Over this he wore a green haori with white trimmings, and around his waist a brown sash with a fringed trail wrapped around his waist twice.
He also wore light-brown platoon sandals with straps in the same color as his kimono and nail polish on his fingernails and toenails in matching blue green color. When wearing this outfit, Haku's long hair was gathered in a white bun holder, while two locks of his hair fell loose framing his face, bound with metal hair cuffs at the ends. Haku also wore a black forehead protector with the Hidden Mist Village's symbol upon it. When in battle or moving covertly, he wore a hunter-nin mask on top of his forehead protector, which was white with thin, curved eye-holes and a red wavy design in place of the mouth, as well as the Hidden Mist Village symbol etched in the top.
Haku was a good-hearted, compliant, and eager shinobi, believing that a person becomes truly strong when they have someone important to protect. Despite his talent for battle, and incredible abilities, Haku disliked needing to kill others in his role as a tool, and avoided doing so whenever possible. When forced to face an opponent, Haku did all that he could to avoid inflicting great harm, even putting them into a death-like state to prevent them from fighting further, as he did to Sasuke during their battle. Before he met Zabuza, he suffered from a belief that he was unnecessary, and served Zabuza because he wanted to feel useful.
Immense Speed and Reflexes: One of Haku's defining battle-traits was his sheer speed. He was very fast with his attacks, such that Sasuke could not follow his actions until he had reawakened his Sharingan. Upon that moment, Zabuza was shocked that Haku would actually lose to Sasuke in terms of speed. His speed is so tremendous that he was able to quickly close the gap between Zori and Waraji and take their swords from them before either of them realized what had happened. His speed increased to incredible levels using his Hidden Jutsu: Crystal Ice Mirrors, making it appear like he was in all the mirrors at once at one point while he was just travelling in between them at extraordinary speeds. It was such that he could launch several senbon from all the mirrors, looking like he was literally in all of them. His speed could easily match with Captain Soi Fon, a highly skilled Shunpo user without effort, much to the latter's surprise.
Expert Hand-to-Hand Combatant:
Master of Stealth and Assassination:
- Zabuza Momochi (Best friend and master)