Kig-Yar Major

Jackal Major is a rank for more experienced Jackals of the Covenant, equivalent to that of an UNSC corporal or sergeant. They are characterized by their orange shields, and usually wear armor that is golden brown in color, though this is not always the case. They are seen commanding Jackals Minor or lesser Grunts in combat.

In Halo 3, their shields appear to be light purple.

Appearances
They appear in almost every level in Halo: Combat Evolved, Halo 2 and Halo 3, with a few exceptions, such as The Pillar of Autumn, The Library, Keyes and The Maw in Halo: CE , The Arbiter, The Oracle and Quarantine Zone levels in Halo 2. They are not in the Halo 3 levels Floodgate, Cortana, or Halo.

Combat
Jackals Major almost always wield Plasma Pistols, which is their standard weapon, with which they are fond of overcharging. Be very careful when attacking them from the front. These Jackals are trickier than their less experienced counterparts. They are better at blocking themselves with their shields, and can usually roll out of the way of a Frag Grenade. The best way to kill them is to Melee them, or use a M6C Magnum and land a head shot for an instant kill. This will also work with the Covenant Carbine or the BR55 Battle Rifle as well, or alternatively using a Sniper Rifle to kill them from afar. With precision weaponry(to help combat Jackal shields) fire at the shield embrasure on their arm which will cause them to reel back in pain allowing for a brief opportunity for a headshot. This will also occur if you shoot at the small area in the shield where the Jackal fires from. A shot anywhere on its body with a Sniper Rifle is fatal, and the body will fly back. Like all shielded Jackals, Major shields are vulnerable to plasma weaponry, although they take significantly more damage than the shields of the Minor. A single overcharged Plasma Pistol shot will deplete the shield, as will a stream of Plasma Rifle fire. Afterwards, an SMG, Battle Rifle, or Shotgun will be devastating. In the case of the Battle Rifle, headshots are instantly lethal.

Like Jackals Minor, Jackals Major are not tough and should be taken down at your own pace. However, they are rarely found alone, often found leading Lances or Files of Grunts as well as other Jackals.

Halo 3
Though they are not listed in the Bungie.net stats, Jackals Major are likely in Halo 3 as the violet shield bearing Jackals. On Legendary, these are more common then their blue shielded counterparts, and with the Thunderstorm Skull active, violet shielded Jackals are the only shield color that appear, which means that they are of a higher rank than their blue shielded counterparts. In Halo 3, Jackals Major always seem to lead a few Grunts, but are in turn commanded by a Brute.

Trivia

 * The sudden change of the Jackals Major shield color (from orange to violet) is currently unknown, perhaps it was just a scripted promotion following the wake of the Great Schism.
 * It has been confirmed that in Halo 3 the Jackals with the turquoise shields are in fact Minor and the Jackals with the violet and pink shields are Major.,
 * In Halo: Combat Evolved for the PC, it looks like the textures, coloring and all-out graphics were never completed or they didn't transfer from the Xbox to the PC very well. So Jackals Minor and Jackals Major have the same shield color (turquoise). In the Xbox version, the Jackals Major have orange shields while the Minor have turquoise shields.
 * The only point so far in the Halo series where the player has Jackals (Jackal Majors usually) for allies, is the level Sacred Icon in Halo 2.