They're
After all, many of the Navigator Houses are into genetic modification, and perform in-vitro gene therapy on their scions to enhance their abilities, so some oddness might not be too out of order. Plus, the current table means that many Navigators pick up the same mutations as they increase in power - but really, why would fucking about with The Warp result in anything being similar?
Roll 1d100!
01-09 Unusual Skin - your flesh takes on an unusual hue, reflective of your unnatural origins.
Roll 1d5:
1-3 Deathly Pale - much like a corpse that has been left in water, translucent and almost blue. A surprisingly common mutation for Navigators.
4 Yellowish Hue - like someone suffering terrible jaundice, you have an almost bruised appearance.
5 Pitch Black - like polished obsidian, pure dark and menacing.
09-13 Slender Frame - you grow dramatically in height, your limbs lengthening to eerie proportions. You lose 1d10 Toughness, but gain 1d10 Agility. You also gain the penalties of the Size (Hulking) Trait.
14-18 Inhuman Visage - the Empyrean changes your features, leaving you looking less than human - perhaps your nose is little more than a pair of slits, your mouth seamless enough to look non-existent, or your eyes are unblinking and a shade no natural being could achieve, shimmering with the roiling chaos of the Warp. You gain the Fear (1) Trait.
19-23 Teeth As Sharp As Needles -over the course of a few days, you teeth begin to fall out, replaced by hundreds of needle-like extrusions. These teeth regularly shed, but are replaced within a day or so. You gain the Natural Weapons Trait (1d5 Rending, Pen 1).
24-28 Marbled Veins - underneath your skin, your veins are a very obvious black - the seething corruption of your twisted birthright making itself known. You suffer -5 to all Fellowship tests.
29-33 Nictitating Membranes - you develop extra eyelids, that closes horizontally underneath your regular trio. You gain a +10 bonus to Toughness tests to resist being Blinded, and a +5 to any attempts to resist Warp-related phenomena (by slamming your Third Eye shut).
34-38 Disturbing Grace - your movements seem less real - as you see the winding paths of possibility unfolding before you, your body chooses its own path before the real world can catch up. You gain the Unnatural Agility (x2) Trait.
39-43 Warp-Fed - the energies of the Empyrean surge within you, providing sustenance where food cannot, and your physiology has been altered to the point where you need some small connection to the Warp to survive. You no longer need to eat or breathe - however, in the presence of a Null Rod or other anti-Warp phenomena, you must start taking Toughness tests to resist suffocation (as per the rules for drowning).
44-48 Unnatural Aura - you exude an aura of ill-feeling - animals are wary (as are people), you smell like ancient places best forgotten, or your sheer presence causes people to taste naught but ashes in their mouth - whatever the reason, all Fellowship rolls are made at -10, except those to intimidate or frighten - those gain +10.
49-53 Clawed Fingers - your nails become long, dully shining like some ashen metal, or the bones of your fingers protrude past your skin. You gain the Natural Weapons Trait (1d5 Rending, Pen 1). If your roll this mutation twice, the claws become longer (Pen 2) but you suffer a -10 to any Characteristic Tests involving fine dexterity.
54-58 Gaunt Frame - you are little but flesh and bone. -1d10 Strength or Toughness, whichever is lowest. If you roll this mutation a second time, you lose another 5 points of Strength or Toughness.
59-63 Strange Vitality - your body is flushed with strange energies that help wounds heal, bones knit back together, and barely leave a trace of their passing. You gain the Regeneration (1) Trait.
64-68 Hairless - you are unable to grow any form of bodily hair, and any you may have will fall out almost overnight - no eyebrows, eyelashes, or even protective nasal hairs. You suffer a -5 to Toughness Tests to resist inhaled toxins.
69-73 Unusual Pupils - whether square, like a goat, slitted like a reptile, or a widely variant colour (such as red, yellow, or blue), your pupils reflect the corruption of your soul. You gain a -5 penalty to any Perception checks.
74-78 Stout Frame - you become obese, almost overnight, and exercise shifts little of the flab. Gain +5 Toughness. If you roll this mutation twice, you gain another +5 Toughness, but lose the ability to Run. If you roll a third time, you can only move at your slowest speed increment without assistance, lose -2d10 Agility and gain the Size (Hulking) Trait.
79-83 Warpsight - more and more, you rely on your Third Eye to guide you, until eventually, the Sight that the Navigator Gene grants you starts to leak over into your view of realspace. The souls of those around you shine like beacons, psykers are miniature infernos, and the creatures of the Warp linger around, sharks sniffing at the blood of those around you. You can see the souls of those around you - all Awareness Tests gain a +10 bonus; however, any Scrutiny Tests suffer a –10 penalty - you are less able to see such mundane things as facial expressions.
84-88 Weakness of The Flesh - your flesh is barely held on at the best of times, but under duress it seems to slough from you like wet paper. You lose one Wound permanently, and all Critical Damage rolls are treated as though they had rolled one higher. If you roll this mutation again, the effects stack up to three times (so, lose up to three wounds and treat Critical Damage as up to three points higher).
89-93 Twisted Frame - your flesh twists back on itself, and your bones curve in all the wrong places. You cannot Run and lose 1d10 Ag. If you roll this mutation twice, you cannot move unassisted, and lose another 1d10 Ag.
94-98 Disturbing Voice - screeching like nails down a chalkboard, or so low as to make bowels loosen, your voice is a horror to behold. You suffer a -10 penalty to any Fellowship tests involving speech, but gain +10 to any Intimidate tests involving speech.
99-00 Maddening Clarity - your senses have been altered by the Warp, extending out from your body and sensing things man was not meant to know - colours hold dark shades not fit for mortal eyes, sounds echo with the laughter of thirsting Gods, and every taste echoes with a thousand forbidden pleasures. When you open your Third Eye, the Warp seems even stranger than before... almost inviting. You gain the Unnatural Perception (x2) Trait, but also immediately gain 2d10 permanent Insanity Points, and 2d10 Corruption Points.
Should you roll the same mutation twice, reroll - unless otherwise stated in the mutation's description.
You are, of course, free to work any of these as you wish - like Unusual Pupils representing cat-like eyes, or milky cataracts, or just a strange colouration (even albinism). Some might work out kinda weirdly - like granting mutually exclusive bonuses or extras. A good example would be Stout Frame and Weakness of the Flesh - extra Toughness, but also a lot more vulnerable. GMs and players should discuss the best way to integrate both mutations (so, your physiology is tough, you resist poisons well, and your bodily integrity is sound - but some Empyrean rot has settled underneath your skin, letting it slough away at any opportunity, and once it gets past that outer layer of fat, there's nothing there), or, in the case of ones which are totally at odds with existing ones, re-roll - but don't let this be an excuse to get rid on undesirable rolls! Navigators must suffer the fruits of their cursed bloodline - it's all part of the GrimDark.
Legal Note: I have reproduced, without permission, items from a property owned by Fantasy Flight Games. I do not own any of the terms used (including Navigator, Mutation Table, any of the Characteristics, and the word "The"). I'm doing this as a non-profit gig, so please don't sue me. To be fair, FFG aren'tThe Evil Empire sorry, Games Workshop, so I'm sure I'll be fine. Just saying.
You are, of course, free to work any of these as you wish - like Unusual Pupils representing cat-like eyes, or milky cataracts, or just a strange colouration (even albinism). Some might work out kinda weirdly - like granting mutually exclusive bonuses or extras. A good example would be Stout Frame and Weakness of the Flesh - extra Toughness, but also a lot more vulnerable. GMs and players should discuss the best way to integrate both mutations (so, your physiology is tough, you resist poisons well, and your bodily integrity is sound - but some Empyrean rot has settled underneath your skin, letting it slough away at any opportunity, and once it gets past that outer layer of fat, there's nothing there), or, in the case of ones which are totally at odds with existing ones, re-roll - but don't let this be an excuse to get rid on undesirable rolls! Navigators must suffer the fruits of their cursed bloodline - it's all part of the GrimDark.
Legal Note: I have reproduced, without permission, items from a property owned by Fantasy Flight Games. I do not own any of the terms used (including Navigator, Mutation Table, any of the Characteristics, and the word "The"). I'm doing this as a non-profit gig, so please don't sue me. To be fair, FFG aren't