The Space Marines were legendary defenders of humanity. Famous for their phrase, "Know No Fear". But the veterans of Macragge did know fear. And it's name was-
THE SWARMLORD
The Ultramarines beat a quick retreat, fleeing from the battlefield as fast as their genetically enhanced legs could carry them. All around them, their fellow space marines laid face first in the dirt, moaning in exhaustion from the brutal beatings their bootys just took.
All of them had their Omega branded granny panties stretched out of their armored pants in various butt clenching ways. Each more painful than the last.
And all done by the talons of the Swarmlord. Each of her four hooked blades had some remnants of ripped underwear still hanging from them.
She stalked across the decimated battleground in all her twisted beauty. She was still a hideous monster, massive spiky and completely alien to anything humans knew. But on top of that, she sported a pair of massive double-D breasts that bounced freely in the wind with nothing to contain them, and a booty so big only a monster like her could wield it.
It was a strange combination: spiky chitinous armor, paired with squishy chubby thighs, wide curvaceous hips, and a pair of cheeks so big they'd qualify as a "Heavy Detachment".
A mix of sexy and monsterous. That was the Tyranids whole MO.
It was also a marvel the Swarmlord had undies big enough to fit her. But the Tyranids made their own now, the same way they made their troops. So all their underwear was custom made to fit. So despite having a massive ass, the Swarmlord's equally massive black, red, and blue granny panties fit perfectly.
No natural wedgies, no ripping, no accidental mooning. Even as she stomped across the battlefield leading her troops against the fleeing Ultramarines, her mammoth sized cheeks bounced and jiggled at each step. But her underwear stayed in perfect place.
The same could not be said for her enemies though. Many had their underwear peaking above their pants line, or were sagging too much, exposing their naked cheeks.
Case in point: as the Swarmlord chased after her fleeing foes, she came across a straggler. An Ultramarine captain crawling along the ground, wearing resplendent decorated armor, except for her butt which was peeking out of her armored backside. She was trying her hardest to follow her sisters or perhaps pick up her weapon.
But a simple cloven hoof/clawed foot being brought down on her back was enough to stop her.
Now the Swarmlord was at a predicament.
She could either push forward to chase the fleeing astartes or stop to quickly play with the bottom of the one beneath her.
Or, then again, her troops could use a little more discipline. Looking out at the assembled horde of Hormagaunts, a mixed group of male and female shortstacks, milling about and chomping at their own claws. She could see they needed some attention too.
Which should she choose?