Gatō

was a shipping magnate that takes control of the Land of Waves.

Background
Gato was a powerful shipping magnate whose shipping company was actually a front for much shadier activities, such as smuggling illegal goods and dealing drugs. He took control of the Land of Waves' shipping routes and created a monopoly by isolating the country from the outside world, preventing free import and export and turning it into an impoverished, hunger-stricken country in the process. He was a cruel, greedy man, also responsible for humiliating and killing Kaiza in public for being the country's hero. Kaiza's death had the effect of demoralising the people of the country, to the point that they no longer had the courage to stand up to Gato. Gato was protected by two bodyguards, Zori and Waraji.

Land of Waves
Gato hired Zabuza Momochi and his men to assassinate Tazuna, and stop him from finishing the bridge, which would connect the Land of Waves to the outside world and allow its economy to recover. After Zabuza's arms were broken in battle by Kakashi Hatake (who was hired to defend Tazuna), Gato assumed that Zabuza would be unable to complete this job, so decided to have his own swarm of thugs to finish the job and kill Zabuza. Since Zabuza was still able to wield a kunai in his mouth, this mistake cost Gato his life. (In the manga, Zabuza chopped off Gato's head with the knife after being struck by several of his cronies. In the anime, Gato was stabbed and slashed several times, then knocked off the bridge.) Zabuza died, and the renegades were scared away by Kakashi, Naruto, and the combined force of the villagers. The bridge, described by Kakashi as "the land's hope", was completed, and named the "Great Naruto Bridge" by Tazuna.

Trivia

 * His name is spelled with and without a circumflex in the English manga. The revised Hepburn romanization is Gato. The first official data book spells his name as "Gatoh".