Korobi is a ninja from Sunagakure and a subordinate of Gaara, along with Yaoki. Korobi was assigned on a mission along with Yaoki and Gaara to stop a group of bandits that were located between Suna and Konoha which Team 7 were also assigned to. He was shown to be cowardly and wimpy when Gaara due to Gaara's killing impulses which he got rid of after Suna's invasion. When Gaara was caught in a trap by Suna's assassination squad, he told Korobi and Yaoki to get away. Naruto runs into them, learning that Gaara was captured and asks them why they abandoned their friend. Korobi and Yaoki both wondered if Gaara is their friend. Korobi and Yaoki both assisted Naruto in rescuing Gaara. After their mission was finished, Gaara asks Korobi and Yaoki what they said to him and they happily say they're his friends.

(source: Narutopedia)