Magma Corers, large creatures that appear to be related to the Carnifex, dig and dissolve their way through the sedimentary and igneous rocks down to the mantle and the magma. No specimens of this creature have yet been procured for study by the station, so detailed analysis of biological countermeasures to extremes of temperature are speculative at this time. The residual minerals exhibit molecular disruption similar to that found on Tyran. Presumably these creatures utilise some psychic matter-manipulation or agitation to facilitate this amazing feat. As they tunnel, they secrete a vitrifying gel which coats the tube and prevents its collapse until the tap is deep enough to begin expelling the compressed gases. In areas where magma is sufficiently caustic, the low viscosity lava will typically erupt releasing huge quantities of dissolved gases. In areas where the lava is acidic and viscous, explosive eruptions and pyroclastic flows have occurred. This results in significant loss of life to all indigenous creatures within miles of the occurrence. Some Tyranid creatures could survive around the periphery of the blast and gas cloud but the intense heat is sufficient to cause the demise of any caught within the cloud. It is unknown if the Magma Corers survive once they reach the 35-40 km depth at which this process is initiated. The tenacity of Tyranid creatures is remarkable but none should be capable of surviving such conditions; it would seem to be suicidal even for such creatures. The ability of the Tyranids to breed a creature whose sole known purpose results in its death is quite astounding.
"It was terrible. We were excavating a recently discovered Eldar ruin on the jungle world of Entri Secundus when we were attacked by massive burrowing creatures. We had the 4th and 7th squads of the 114th Imperial Guard infantry division there to protect us from the predators in the jungle, but... but we never thought we'd need to look to the ground for our defense! It was terrifying!
One moment, we were operating the blessed excavation machines and the next, we were getting strange readings on the seismotectonic sensors. Suddenly, a cloud of superheated gasses burst forth and before the techpriest or Avis could even scream, the Emperor take them to His breast, melted their flesh off. Then a tremor knocked me off my feet and then there was a loud noise, louder than a melta-charge or the sound a locked leg servo on a sentinel makes when it snaps, and that's when the screaming began.
The 4th squad didn't even have a chance; half of them went right down the gullet of the creature that burst forth quick as I can wink. The sergeant in charge was yelling orders right up until a glob of molten rock took his face off. I don't think I'll ever forget the smell of the burning flesh. Just thinkin' about the caustic fumes makes my eyes water all over again. My courage abandoned me as I saw it crush the remainder of the 4th squad beneath its bulk and I fled for the civilian dropship that the pilot was already sensibly warming the engines up for takeoff. I barely made it. As the dropship took off, I saw the 7th squad fall to more of these creatures as they breached.
Once the soldiers were killed, they converged on our digging machines, destroyed them and then gracefully dove back beneath the surface of Entri Secundus. I can only speculate that our digging disturbed a nest of these beasts. I know they are terrible creatures, but I can't help but feel a sort of awe at the majesty of their ability to travel through solid rock; no technology we possess can even come close." ~Testimony of tech-archeologist Gareth Trazt at his trial for desertion of his duty to excavate the Xenos ruins on Entri Secundus. Executed as a heretic the following day.
Imperial Designation: Magma Corer
Common Names: Tunnel Terror, Lavaworm, Hellmaw
Species Name: Tyranicus Subterra Vulcanus
Little is know about Magma Corers, as no specimen has ever been captured nor has the body of one been recovered. What is know is that they are large worm-like creatures capable of burrowing through solid rock, though by the means of this ability reside in the realm of hypothesis. One theory is that they are psychic beings capable of molecular manipulation and rend the rock by sheer force of will as they plow along. Another is that they have glands on their heads that spray forth a horrifically caustic mix of bio-acid that burns through rock at an incredible pace.
In either case, they are as capable as travelling through solid rock as an aircraft through the air. Survivors of the rare magma corer attacks describe the creature as leaping from the ground beneath them and crashing into the troops, much like a breaching whale as seen in the old motion pict-captures of ancient Terran history. Magma Corers are rarely, if ever, provoked into attacking; it is usually the younger, immature larva of the creatures that attack without provocation. Older Magma Corers are never seen on the battlefield, as they are already deep below the surface fulfilling their mysterious purpose for the Hive.
Magma Corer Larva
WS4|BS2|S10|T8|W4|I2|Ad6|Ld7|Sv 2+/5+ inv.
Brood: 1-3 larva, although they do not arrive on the field at the same time and operate independently of the other. Fielding Magma Corers requires that both players utilize multiple detachment rules.
Bio-weapons: Its own massive body, with which it crushes and rolls on enemies, and its fearsome maw (see special rules of the maw below).
Mass Points: 2.
Hivemind Powers: The Terror, Warp Field
Immunity to Fire: A Magma Corer is immune to Flamer weapons, as it is built to bore its way down to the layers of subterranean molten rock (I was considering making it immune to plasma and melta weapons as well, but I figured I shouldn't, since fluff does say that they die when they make it to the magma mantle and honestly, if I did that, how would you kill on of these guys?)
Maw of the Beast: The lower jaw of a Magma Corer is split along the middle, allowing the jaw to open sideways to a great degree. This grants the creature the benefits of the acid maw and tusked biomorphs, as well as the implant attack biomorph (this represents the target either having its molecules rended or the horrific acid used to burrow through rock, whichever fate you prefer).
Gargantuan Creature: As a Gargantuan creature all the rules for Monstrous creatures apply to a Magma Corer. As a Gargantuan creature a magma never has to fall back when in combat with a war machine. A Gargantuan creature can still be fired upon in the Shooting phase when engaged in an assault with a non Gargantuan creature. It counts as 15 models for the purposes of enemy morale after an assault.
Deep Strike: A Magma Corer always starts in reserve and must deploy via deep strike, regardless of the rules of the scenario. Such is the size and power of a Magma Corer that if it scatters within 1" of an enemy model it is not destroyed as normal. Instead, move the enemy models out of the way (any enemy models moved are placed in base contact with the creature) and the Magma Corer counts as having assaulted that enemy unit. Roll for each Magma Corer separately to see if and when they arrive.
Caustic Fumes:(This ability may only occur when a Magma Corer is deployed from reserves, and base the scatter die from where it deployed.) During the controlling player's Shooting phase, he may nominate 1 point on the field per Magma Corer that did not enter into play from Reserves. From that point, roll a Scatter Die and 2d6. At the new location, resolve D3 toxin spore mine explosions (if there are no victims to hit, the mines explode harmlessly and do not drift about the field). This represents caustic fumes released from the burrowing Magma Corers pushing to the surface and escaping.
In addition, the Magma Corer is treated as having the Toxic Miasma biomorph in combat.
Erupting Charge: If a Magma Corer assaults an enemy unit via deep strike, it gets to make a special Shooting attack before the beginning of combat (even before defenders behind cover). As it is a special Shooting attack, it does not benefit from the Maw of the Beast or Gargantuan Creature special rules. The attack has the following profile.
Rng. Special| S4 | AP- | Assault 2d6, Rending
(This special attack represents the ground practically exploding beneath the defender's feet as the Magma Corer plows upwards. The logic for its accuracy being based on the creature's BS is to show the randomness of flying rock (rather than just saying that the unit is outright hit d6 times) and the rending special ability represents the occasional spurt of molten rock hitting a trooper, which would be rather unpleasant by my reckoning.)
Swallow Whole: A Magma Corer is capable of swallowing men whole, similar to the special ability displayed by the Red Terror. If the creature hits with 4 or more Attacks in the Assault phase (not counting those caused by its Erupting Charge ability), it can choose to a single enemy model in base-to-base contact and swallow it whole.
You can elect to use this ability if you score enough hits, there is no need to declare the intent to swallow beforehand. Any successful hits in excess of 4 are lost as the Magma Corer is busy getting the victim down the hatch. The swallowed model is removed as a casualty, no roll of any type is needed, nor can any save or wargear save the victim.
A Magma Corer cannot swallow models with:
- A Strength and/or Toughness greater than 5 (yes, this is different than than the Red Terror, who would normally get indigestion from something with a S or T value of 5 or more; a Magma Corer is a frickin' expensive gargantuan creature that requires a separate detachment, thus it gets special treatment)
- Bike or cavalry models
- Anything with an Armour value (i.e. Dreads and other vehicles).
Survival Instinct: If a Magma Corer is down to its last wound and fails an IB test, it immediately dives back down below the surface (treat as below half-strength for VPs).
In addition, the controlling player may elect to have the Magma Corer retreat back into Reserves instead of normal Movement, regardless of how many wounds it has left. A Magma Corer that retreated to Reserves may attempt to reenter play starting on the next turn it would be entitled to do so if it rolls the appropriate result.
(The above text is contributed/stolen from warpshadow.com's 'Wyrd Bearer'. )