Monsters of Grábakr
Genestealers
The basic infantry of the swarm, it is debatable if they are truly the ancient strain repurposed or a new one made in a similar image. However, either way, the name has stuck. Unlike the Genestealers of old, Grábakrs Genestealers do not appear to bother tainting the bloodlines of their prey, instead simply slaughtering them. Physically, they appear similar, though their chitin plates are much smaller and more streamlined. Autopsies have shown they have a massively overdeveloped nervous system, with thick nerve bundles distributed throughout their bodies, including their claws and fangs. They show relatively little variation, but will sometimes bear strang organic foci in place of one or more sets of arms. In battle they are pure melee troops, relying on psychic powers to close into melee before butchering their prey.
Broodlord
A larger Genestealer usually seen one to a brood. Compared to its brood they are a few feet taller and tend to have somewhat enlarged heads. They appear to act as local command nodes and serve as living foci for group power usage. They are not true synapse creatures but seem to create local hive minds for tactical purposes. Eliminating them has been observed to notably reduce the effectiveness of nearby Genestealers for a brief period. This is easier said than done as they seem to possess a form of battle precognition, and are surrounded by bioforms that will die for them without hesitation. Unlike common Genestealers, they will sometimes be equipped with advanced biomorphs, such as Bonesword or bioplasma.
Phase Ravener
A serpentine bioform twice the height of a man, and equipped with four long talons. Phase Raveners seem able to dive into some sort of extra-dimensional space for minutes at a time. While its nature is not known, it has been confirmed not to be within the warp. It is suspected they are making short sojourns into the strange realms that more esoteric Necron technologies and units make use of. The accuracy of their return trips vary drastically, and it is suspected their ability to pick a reemergence point is dependent on the present conditions of the strange realms they move through. They possess a notable healing factor, something the hostile dimensions they traverse demand, it is not uncommon for them to return to realspace injured or even missing members of their brood. However, they seem able to bypass almost all forms of interdiction, allowing them to emerge from unexpected angles. In combat their claws seem to act as potent foci for all manner of severing or cutting powers, allowing to cut through even the thickest armor with great ease.
Warriors
Potent bioforms created to act as elites Warriors remain largely unchanged in appearance from their ancient counterparts. No longer always, true synapse creatures, warriors are now often pure combatants. Usually equipped with potent living focis warriors are potent psykers, with power depending on their strain. Melee focused variants are often capable of extremely long-range teleportation and potent biomantic enhancements. A number of ranged breeds also exist, often using potent illusion based powers to allow them to rain death with deadly bioweapons with near-complete impunity. Variants that use solely offensive powers exist and are capable of reaping terrible destruction, often burning themselves out with the sheer power they channel, dying to eliminate high priority targets.
Biovore
A form of living artillery. Biovores are large and by the standards of Grábakr relatively ponderous. They carry potent spore mind that they hurl into battle via applied telekinesis. They appear able to use a form of biomancy to enhance the killing power of spore mines at significant distances. When not in combat it is able to achieve significant strategic mobility by applying its telekinesis to itself, however, it cannot do so while firing.
Zoanthrope
An improved version of the Zoanthrope strain. Grábakr Zoanthropes retain the general body shape of their forbears but have fully repurposed their once vestigial body. Their bodies have been remade into potent psych channels, acting as grounding rods for the vast amount of power they channel. Their drifting tails melt the earth below them as they pass, and their touch can reduce tanks to molten slag. Zoanthropes are immensely difficult to damage, shielded as they are by an invisible field of psychic power, they fill the role of heavy assault creatures, moving to the fore when durability is needed. Safe behind their powers they lash out with devastating bolts of psychic energy as their flesh easily repairs any damage that does not slay them outright.
Necropthrope
A specialized form of synapse creature, Necropthropes resemble a zonoathrope covered in spines and strange chitinous funnels. Necropthropes appear designed to take advantage of recently freed up psychic bandwidth, their powers growing as creatures around them die. The power boost is temporary, presumably lasting only until the replacement unit awakens, but until then they can become devastating psykers. Necropthropes typically focus more on repositioning or augmenting Tyranid forces. They have been observed psychically devouring nearby Tyranid units to fuel spectacular displays of psychic might. In recent engagements, they have been observed to reanimate slain Tyranid units, puppeting their corpses to great effect should they be sufficiently intact. A worrying reminder that the swarm is adapting to face foes other than the Necrons.
Haruspex
A specialist breed that is only rarely deployed, its body is essentially a vast tendril filled maw on legs. Grábakr Haruspexs poses immensely potent but short-ranged telekinesis. The power they can exert falls off with exceptional speed as the distance to their center point increases. Their power is hinted somewhat in proximity to their tendrils. They primarily kill by ensnaring prey with a mixture of their tendrils and telekinesis, before dragging them into their mouth where they are crushed with the beasts full psychic might. When confronted with distant foes, they will fire spheres of super-compressed matter, the speed and density of these projectiles make them immensely deadly. To date, nothing drawn into a Haruspexs stomach has survived, with even advanced terminator suites being crushed into a fist-sized sphere of ultra-dense alloys.
Hive Crone
Grábakr hive crones have radically departed from their forbearers. Forsaking wings entirely they fly solely by applied psychic power. They are incredibly fast and possess near-perfect maneuverability. Hive crones posses a potent form of stealth focused phasing, while easier to disrupt and slower to initiate than most, when phased they are utterly undetectable by almost any nonpsychic means the trust poses. Mercifully, this does appear to be two way, with crones unable to see when phased. However, they appear able to track how far they have moved, and are still guided by the hivemind. This enables them to remerge near their targets despite flying blind. Absent spotters a brood will typically leave a few members unphased to coordinate. So far they have not proven inordinately difficult to track via psychic means, by those few psykers who can pierce the shadow of the warp. They are typically armed with a small swarm of living missiles known as tentaclids. Typically tentacles will erupt into a spray of hyper-concentrated acid, however, some will detonate in a psychic effect of some kind. Thes living missiles were originally the crones only armament, but as time passes they have begun carrying deadly short-ranged weapon morphs.
Hierodules
A potent knight titan sized combatant, Hierodules serve as heavy assault units. Specialized in phasing and teleportation, they are immensely mobile even by the high standards of Grábakr. They typically carry either 4 claws and an acid-spewing symbiont, or two claws and a pair of deadly short-ranged bio cannons. Hierodules are inordinately deadly at close range, as they are able to phase their projectiles through their targets armor, flooding internals with potent acid or biological projectiles. Over the years, variants carrying less deadly but longer-ranged bio cannons have appeared, as the swarm adapts to facing less durable foes.
Hierophant
The heaviest assault ground weapon used by hive fleet Grábakr. A monster of immense psychic power, its form bulges with sacks of grey matter and its titanic frame strains to contain its staggering psychic might. All examples are capable of rapid and long-range teleportation, as well as advanced phasing techniques, each strain carries a second discipline. Shaper hierophants are biomancers of staggering power. they can not only enhance but reshape themselves and nearby forces. Flash reforging biomass into forms more suited to the present situation. Force Hierophants are Telekinetics, and stand at the eye of a telekinetic hurricane, deflecting even anti titan fire with ease while staggering forces tear apart anything unfortunate enough to be within range.
@Durin the list of monsters trying to eat our face. they have links going to the bioform they are based on to give an idea of what they look like.