HRUNTING/YGGDRASIL Mark IX Mantis

"Like the Cyclops mech suit but bigger and better and badder."

- Black-Box

The HRUNTING/YGGDRASIL Mark IX Armor Defense System, commonly known as the Mantis, is a powered exoskeleton/armored fighting vehicle used by the UNSC Marine Corps after the Human-Covenant War. It is derived, if tangentially, from the HRUNTING and YGGDRASIL teams' earlier Mark I Armor Defense System.

Design details
Standing roughly twenty feet tall, the Mantis is similar in appearance to the larger Cyclops Mark II, which itself was the evolution of another HRUNTING project. Its spindly legs and tiny "thorax" give the Mantis a passing resemblance to its namesake, as do its weaponized arms. There are two versions of the Mantis, both of which have an anti-matériel machine gun on the right arm and a missile pod on the left. One variant has a larger-caliber cannon and surface-to-air missiles; the other version has an M655 20mm heavy machine gun and M5920 35mm surface-to-surface missiles. Though it lacks the firepower and durability of the M808 Main Battle Tank, the Mantis is far more maneuverable and is equipped with energy shields.

Service history
The earliest known use of the Mantis occurred in early 2553, when one was delivered to Kilo-Five aboard their prowler. The Mantis continued to be in use only by select highly classified ONI units and the, which carried a number of Mantises by 2557. After Infinity was drawn inside the shield world Requiem, Spartan John-117 used a Mantis against Covenant remnant forces in the vicinity of the ship's crash site. Several Mantises were used to defend Ivanoff Station. Later that year, Infinity 's SPARTAN-IV complement used a version with scaled-down weapons in War Games training. During the Second Battle of Requiem, Fireteam Crimson was sent to rescue a squad of Marines trapped behind enemy lines. During the rescue attempt Crimson was met with overwhelming Covenant forces, Commander Sarah Palmer ordered mission handler Robert Dalton to deploy several Mantises to aid Crimson in holding off enemy forces. During the attack on the Infinity, Lieutenant Murphy brought in a Mantis to support Fireteam Crimson in order to clear a landing zone.

Gameplay
The Mantis has two variants, both in canon and in gameplay. The more powerful model, featured in the campaign and Spartan Ops, is designed to provide the player an almost overwhelming advantage. To promote more balanced competitive play, the Mantis has less firepower in War Games and has anti-surface rather than anti-air missiles. The player may fire all five missiles by holding the left trigger, while tapping the trigger fires only one missile, similar to the plasma launcher in Halo: Reach. The player can stomp the ground with the Mantis' legs by pressing the melee button. The Mantis is also capable of crouching to lower its profile.

Production notes
During the early concept phase, 343 Industries considered implementing the HRUNTING/YGGDRASIL Mark I powered exoskeleton from the Halo Legends short Prototype. Later concepts derived from this design featured a larger exoskeleton that would cover the wearer's MJOLNIR armor. Designing the Mantis required months of playtesting, much of which involved tweaking the speed of the "stomp" move. One of the biggest concerns was making it clear when a player is reloading the Mantis' weapons; originally, the Mantis held its arms forward as the weapons were reloaded. Due to playtesters' feedback, the animation was changed so that the mech lifts its arms when new ammunition is being fed.

List of appearances

 * Halo: The Thursday War
 * Halo 4