From Halopedia, the Halo wiki
J-011-422 is the EC# of a Covenant Jackal. In 2552, this individual participated in the Battle of Mombasa, holding the rank of Sniper. However, he discarded his Type-50 particle beam rifle for a Needler and a Kig-Yar point defense gauntlet. According to a historical account, a Jackal of his rank would usually keep its Beam Rifle, and not rely on an energy shield, as to better aim with both hands.
Years later, a model of J-011-422 was made and placed in the John-117 Monument in the Museum of Humanity in 2607.