Za'zayara-pattern Harvester

The Za'zayara-pattern heavy excavator or colloquially the Harvester, is a Covenant walker used during large-scale excavations and in the search of artifacts. An exceedingly rare sight in the field, one was used by Jul 'Mdama's Covenant during their occupation of Requiem.

Design
Harvesters are the biggest Covenant land vehicles to date, with only the "Super" Scarab and being comparable in size and rivaling naval warships in scale. Generally used in long-term invasions, they are not commonly seen by UNSC personnel. Much like the Scarab, it is composed of a meta-colony of Lekgolo known as Sbaolekgolo; this is evident from exposed Lekgolo worms seen in its interior.

While all Covenant technology shares a generally organic design aesthetic, the Harvester's features are significantly more ornate and conspicuously insectoid than most Covenant constructs. It is much more beetle-like in appearance than the Scarab due to its overall shape, heavily textured outer "skin" and a hatch at the front of the machine that resembles a mouth and eyes. The interior is composed of multiple massive chambers that resemble dark subterranean caverns, linked together by smaller hallways and illuminated with pale green light.

The Harvester is compatible with the power supply of a. As a result, a Lich's power supply can also be used to power a Harvester and fire its plasma drill.

History
In 2557, Gek 'Lhar deployed a Harvester in the debris field left by the destruction of Trove shield world. However, the debris field and presumably the Harvester were destroyed by a bombardment of nuclear weapons from a massive UNSC fleet, forcing Gek and his forces to flee the system.

In 2558, a Harvester was deployed by Jul 'Mdama's Covenant to excavate a buried Forerunner facility holding one of the three Requiem slipspace artifacts. During the Requiem Campaign it was disabled by Fireteam Switchback, who mysteriously vanished in the firefights afterwards, leaving no bodies or signs of struggle, only their IFF tags. Fireteam Crimson was sent in to investigate. Crimson managed to kill the remaining crew of the Harvester and further disabled the walker by destroying several consoles inside.

Sometime later, the Covenant retook the Harvester and captured several scientists to reactivate the walker, but they were not successful because the power supply was destroyed. When Requiem was put on a collision course towards the star it was orbiting, Fireteam Crimson was sent back to the area to reach one of the artifacts that was preventing the from leaving the planet. After discovering that the artifact was buried behind a rock wall, it was realized that the Harvester had been brought in to excavate the artifact. Though the Harvester now had a shield blocking the entrance, Crimson took out nearby anti-aircraft defenses and a Pelican took the shield. Crimson eliminated the crew and rescued the scientists who revealed their failed effort to reactivate the Harvester. Needing a replacement power supply, Roland came up with a solution. Crimson was then deployed to "Apex" to steal the power supply from a Lich to replace the destroyed supply on the Harvester. Crimson returned to the Harvester and cleared out the minimal Covenant forces that had reoccupied the walker while they were gone. With the Lich power supply, Crimson was able to reactivate the Harvester and use its plasma drill to bore a hole into the caverns containing the structure with the Forerunner artifact as the planet fell apart, causing falling debris to strike the Harvester. The Harvester was destroyed when Requiem was consumed by its star.

During the events on Aktis IV, Jul 'Mdama deployed several Harvesters to destroy all of Sali 'Nyon's rebel hideouts. One of these Harvesters would save Dr. Catherine Halsey from being captured by Spartan Sarah Palmer.

Trivia

 * Throughout the Halo 4: Official Game Guide ' s digital Spartan Ops walkthrough, the Harvester is constantly referred to as being a Forerunner construct.
 * Like the Scarab and the Locust, the Harvester is named after an arthropod, more commonly known as harvestman or daddy longleg.
 * It's not made clear in-game how the Harvester encountered in Spartan Ops had its power supply destroyed. While the game has the player destroy two consoles during the initial raid on the machine, they do not target the central console where the power supply was located, although the damage caused by the destruction of the other consoles might've fried the power supply even though the console it was in was untouched.

List of appearances

 * Halo 4
 * Spartan Ops
 * Halo: Escalation
 * Halo: Renegades