Hanzō was a rather muscular man of average height, with long blond hair reaching down to his back and a prominent scar on his right cheek. In the manga, he had unusual eyes that displayed dark sclera and light colored irises, similar to Kakuzu's. In the Naruto anime, his eyes were portrayed with a normal white sclera and brown irises. On the left-side of his abdomen, he bore a distinctive cross-shaped scar received from implanting a salamander's venom sac within his body. He had a dark hat on his head and his lower face was mostly obscured by a helmet-like respirator, which he used to keep his own poison at bay and that differed from the ones worn by other Amegakure shinobi, as it was notably larger and featured two filter cartridges instead of the typical one. The upper portion of this mask bore the symbol of his village and was mirrored by four indentations on the part covering his mouth.
His typical attire consisted of a loose wetsuit-like outfit typical of his village, accented by bandages wrapped around his wrists and lower legs, a flak jacket with swirls on the chest-plate, standard shinobi sandals and a dark cloak that reached down below his waist. Underneath this wetsuit, he donned a dark, short-sleeved, midriff shirt which exposed his lower abdomen.
Hanzō was a very security-conscious individual, trusting no one. He was guarded twenty-four hours a day, and did not allow anyone in his presence, even children, without being thoroughly searched. He cared greatly on his position as village leader, and dealt with threats harshly. This obsession with security deluded Hanzō into thinking of preserving the great skills he has amassed, when instead it caused his skills to deteriorate due to lack of practice.
Although he viewed the Five Great Shinobi Nations as his enemies, he was still willing to ally with foreign nations, even those who had caused him great harm, in order to remain in power. He was also willing to betray people without remorse, leading the Ame Orphans and their team into a trap, then attempting to have them all mercilessly killed; this betrayal, ironically, led to his own demise.
A long time ago during his youth, Hanzō had once sought the ideals of "peace" and even attempted to achieve this belief through the unification of the Five Great Countries. His conviction was so great, the Hidden Rain Orphans, despite not being subordinates of his, wore his forehead protectors as proof of their dedication to his cause. However, after realizing that such a method would only bring about perpetual war and thus, leave only death in its wake, he cast aside this conviction. Afterwards Hanzo became devoted solely to the preservation of the power he had previously amassed, growing arrogant of his own skills in the process and leaving him unaware that they had instead dulled considerably, due in part to the lack of refinement brought about through practice. Even by the time of his death, Hanzo still couldn't comprehend how someone he had once defeated, could have grown more powerful than himself.
A distinctive trait of Hanzō, however, was his belief in the faith of people. He believed that a strong faith would have survived the death of its owner, living on; faith, according to him, wasn't visible to the eyes, but could only be perceived through a fight. He had great respect for the ones with a strong faith, as seen when he spared the lives of many strong-willed opponents he defeated, demanding their names in order to call them heroes in spite of their defeat. If he also sees his defeated foes have potential, he will let them live and even give them titles in recognition of their strength and conviction and demand that they are to refer themselves to the title he gives them in exchange for their lives. In the anime, he seems to enjoy a decent battle, allowing opponents he sees potential in to live to become stronger and challenge him again one day. He claimed his faith laid in his will to bring peace to the world, which, despite his harsh words and his attitude in later stages of his life, seemed to have lived on, as seen when, before releasing a poisonous cloud from his venom sac and losing his free will to Kabuto Yakushi's Summoning: Impure World Reincarnation, he entrusted his faith to Mifune.
Body Modifications: As a child, Hanzō was implanted with the venom sac from a black salamander, which resided within his village upon its death, leaving an identifiable scar on the left-side of his abdomen. This procedure conferred to him the poison-related abilities of the creature, amongst which were an enhanced resistance to poison and the alteration of his body chemistry so that he too became toxic, so much so that even his breath would intoxicate those in the immediate vicinity. This poison was deadly, causing victims to experience excruciating pain until they succumbed to numbness, where these effects would then progress to complete paralysis and ultimately death within a period of two days from inhalation. To preserve the safety of others, Hanzo always breathed using a respirator and carried a small vial of antidote with himself, although even immediate ingestion of this did not guarantee survival. The fear that this very implantation produced, earned him the epithet of "Hanzo of the Salamander". Fighting without his mask granted Hanzo a great advantage over his enemies, but also bore a considerable risk for himself. If the venom sac were ever ruptured after receiving a direct wound, the resultant poisonous cloud released as the toxin vaporized would immobilize him for several seconds, presenting a significant opening for his foe in spite of the venom still remaining non-fatal to Hanzō. The mask completely alleviated this risk and so he resolved to remove it only when pitted against weaker enemies that he could defeat without consequence, while keeping it on when in the presence of stronger opponents who could have exploited such a weakness.