The Devil's Own Space Cows & Actual Play

The old spacer looked into the astronaut's eyes as he poured the last of the Old Earth Whiskey. The gravity was just enough to let the old man do his job. The kid was 19 cycles out & still wet behind the eyes.  
"They was spacecows but like none I've ever seen. They came outta no where & the herd was on green fire. The sort of hobgoblin fire my ma used to talk about. I'm telling ya they left our slow boat spinning as the came for us. The verse turned on a dime as we spun there. The damned thing though some of them seemed to pass through us. It was like we weren't even there for 'em  or something. 
  Some of our controls burned & burned even as the herd thundered around us. They passed over the ship & left blazing foot prints in the hull. That thunder was coming from our hull! There's no sound in space but they left it there! 
 They took McCready as one passed through our hull! One minute he's at his post an next he's seat's empty." 
The old spacer shook his head & the cybernetics whined with the action. He looked at his own arm & grabbed a bottle of the good stuff. "Well son, let me tell you of  My experience with the herd." 
The kid's eyes lit up with terror at the tone of the old bartender! 

Space is filled with all manner of deadly things  but none so strange as the Space Bovines that seeming roam between the planes & the Outer Darkness. Where they come from no soul knows but they leave death & disease within their wake! The herd is only partially real in this space &  exists within the other. They take half damage from energy weapons but regenerate hit points at 1/2 per round! They're attacks are as a demon & they can melt metal with 2 rounds with 20 % of damaging hulls of space craft. There are 300 to 600 head of them per herd.
Their origin stories vary with the telling! Roll 1d10  on  the story matrix

1. They belong to a demon king who must let them roam to keep the balance of the universe 
2. The herd is actually spacers who have made a pact with Shatain himself & are looking to expand the herd 
3. Those aren't cows their demons in disguise & no spacer will ever possess them 
4. Those are simply Shaitan's cows & they go where they will but must return to hell at the end of the rotation of the galaxy 
5. I'm telling you those are the souls of those that dead in the Atomic Fires of old Earth 
6. The Herd is a weapon of mass destruction released upon the universe no demon or devil controls em 
7. Its a corporate experiment to keep the people in line there isn't a herd at all 
8. Those are the souls of CEOs of all the evil corporations who have sold their souls to Shaitan himself & their hungry 
9. Its demons plain & simple. 
10. Those are the future selves of mankind & they're come back in time to destroy us all! 

The herd is proceeded by incredible events that foretell its coming! Roll 1d10

1. Water turns blood red & tastes of it as well 
2. Random spacers spontaneously combust
3. Hyperspace jumps become random 
4. The gateways into planar space open to Hell itself for 1d10 rounds 
5. Communications is filled with the sounds of the damned screaming 
6. Animals fall over dead 
7. Skies of planets turn other unnatural colors  
8. Meteors appear & then disappear ever 2 rounds 
9. Images of demons & devils appear on the monitors of  pilots in the area for 1d10 rounds 
10. There is demonic laughter across space channels for light years 

The herd has strange eldrith qualities from roam across the planar spaces. 

Special Qualities Roll 1d10

1. The herd can pass through solid matter & there is a 20 % chance they may take a random party member 
2. Hooves of the herd are red hot with the elemental fires 1d4 points of damage for combat 
3. They shoot jets of plasma doing 1d6 points of damage 
4. A crew of minor demons is with the herd 1d6 hit points each 
5. The herd is hungry & can devour anything it comes in contact with 
6. The cows glow with witch fire that does 1d4 points of damage to anyone they come in contact with 
7. Space around the cows is unstable & anyone going near them is teleported 20 feet in a random direction 
8. They are accompanied by the damned (zombies who are very hungry) 
9. There are demonic possessed spacers among them roll 1d20 to see how many 
10. Shatan himself accompanies them (stats of a balrog all hit points) 

These will be used in tonight's game expect a post soon!