ORIGINAL CANON (Excerpt from Pfhorpedia)

The Pfhor juggernauts or Utfoo Heavy Assault Crafts are the strongest enemies in the whole series. In Marathon, the juggernauts have no sub-rank. However, in Marathon 2: Durandal, a major juggernaut was introduced. These living tanks come equipped with giant rotary machine guns, and built-in heat seeking missile launchers. When these war machines are killed they emit a loud high pitched beeping noise, starting their self destruction sequence. Anything within the range of the juggernaut will be killed when the self destruction sequence finishes, and the explosion can be seen and heard from anywhere on the current level.

The Juggernauts design has been changed through the games. In Marathon, their faces are very skeletal looking, and their floating bodies are very round. They have three eyes like most of the Pfhor. In Marathon 2: Durandal their face was simplified a bit and wasn't as skeletal, but more machine like. Their bodies were also given a different shape, the bodies were now more squarish and looked more like a tank. The guns' projectiles were changed to resemble the Enforcer rifle ammunition.

As stated by Durandal in Marathon Infinity, the shields of a juggernaut are normally powered off while they are being repaired. Mjolnir Recon number 54 proved this to be true by destroying several of the assault craft, as well as several empty hunters, on the Armor Platform of the Lh'owon Naval Unit with single shots from the fusion pistol. It is also noteworthy that powered-down juggernauts are equally vulnerable to stray bolts from the Pfhor shockstaff, as well as from hunters.

HD UNIVERSE (Fanon)

[Phase I Utfoo Heavy Assault Eliminator Craft]

The original UHAE tank drone was the Pfhor's longest standing iteration of the 'living craft'. It was designed initially for assaults on technologically underdeveloped civilization. Over the last thousand years the Pfhor endlessly implemented system overhauls but visually remained the same with few obvious changes. It was wide, angular and navigated quietly. The first generation used state of the art Anti-CQC repulsion field servomotors, which also functioned as fail safe cluster bombs. It was equipped with floating point Nar-derived turbine cannons (N-Cannons) and micro warhead torpedoes. Behind the menacing a visage was an enhanced brain extracted from the neural tissue of fallen soldiers. Type One Juggernauts, due to being centered around extreme gravity environments, had poor verticality and just barely lifted off the ground. It required floating only seven inches at max over hard surface in order to initiate fail safe detonation.

[Phase II Utfoo Heavy Assault Finisher Craft]

To maintain status as commanding-AI, the insane Tycho completely redesigned the platforms architecture, following a decade since their embarrassing stint aboard the UESC Marathon. Admiral Tfear used centuries of S'pht advanced warfare to streamline and better adapt to orbital bombardment scenarios unlike Phase I Eliminators. In place of Neural Radicals (brain tissue) were lesser mirror-cores of Tycho's personality. Phase Two Finisher's are equipped with generic homing warheads and are equipped with fixed-position gamma burst cannons . There exists a super rare yet identical 'New Reprise' variant, which is far more deadly, and made of stealth-capable Jjaro alloys. They were rumored to now be piloted by the elusive Artificial Intelligence Thoth.