Midori

was a Chūnin from Kusagakure. He and Tsuba were the personal guards of the Grass Daimyo during the Chūnin Exams. They were assigned to make sure Gaara lost to Sasuke Uchiha, making their daimyo win a bet with another daimyo. When they threatened Gaara to lose, they greatly offended Gaara, who then proceeded to brutally crush Tsuba to death, and then Midori, who tried to flee in terror, died shortly after. Their gruesome deaths quenched Gaara's anger, which saved Naruto Uzumaki and Shikamaru Nara from the same fate.

Trivia

 * Midori literally means "green".