Jirobo is a villain in Naruto and a member of the Sound Four, Orochimaru's elite bodyguards, serving as the muscle of the group. He is a large teenage boy who can use earth style jutsus, and like the other members of the Sound Four, liked to call his opponents "trash" and generally taunt them.
He, along with the other members of the Sound Four, were involved in the Invasion of Konoha, assisting Orochimaru by putting up a barrier to make it so others could not interfere in his battle with the Third Hokage. Jirobo's identity is unknown at this point, but it is revealed when the Sound Four are charged with escorting Sasuke to Orochimaru. After the Sasuke Retrieval Team tracks them down in the forest, Jirobo stayed behind to fend them off while the rest of his team fled with Sasuke in tow. He trapped all five team members inside a stone prison, absorbing their chakra in the process. Shikamaru, the team's leader, offered to sacrifice his teammates and Sasuke, but Jirobo refused, admonishing him and saying that he deserved to die for being a bad leader. As it turned out, Shikamaru only pretended to parley with him to confirm his location, and determine where the chakra flow around the barrier was weakest. Choji successfully broke through the barrier, and stayed behind to fend Jirobo off while the rest of his team went after Sasuke.
Jirobo took pleasure in taunting Choji during their battle, calling him fat and further insulting Shikamaru. Choji had happened to bring his "secret weapon" to the fight, which happened to be three colored pills that increased his strength exponentially. Jirobo was forced to open his cursed seal to fend off his opponent, and even when his strength was at its greatest with the second stage of the seal open, an enraged Choji managed to kill him after consuming the third pill.
Cursed Seal Level One