One day, penny went into Leonard and Sheldon's apartment to "borrow" some milk. Neither of the guys was home so Penny just let herself in. She went over to the fridge and pulled out the milk. She was about to walk out when she looked at the couch. She looked at Sheldon's spot thought of how Sheldon though he owned that spot.
"I can't stand it anymore," she thought angrily. "It's a seat on the couch and Doctor Wackadoodle needs to learn that people are allowed to sit wherever they want."
Penny spitefully walked over to the couch and sat in Sheldon's spot. After a few seconds she thought, "There, I sat in it. Big deal."
Looking around, she though, "What else can I do that grinds Sheldon's nerves?" She spotted the hallway that lead to the bedrooms and grinned.
"Of coarse. He hates it when people go into his room. So that's what I'm gonna do." She got off the couch and walked back the hallway to Sheldon's room.
She opened the door to the familiar nerdy room that was Sheldon Cooper's. Things like Star Wars and Batman figurines and all sorts of sciency stuff were all over the place. Everything was excessively, neatly organized.
Penny walked inside. "Ooh, I'm in Sheldon's room. Oh no," she said to herself. She began touching and picking up various items she saw. She touched the large DNA model, she picked up the Green Lantern action figure, and then she went over to a shelf and looked at what looked like a bunch of glass vials placed in a holder.
Each vial was filled with a strange liquid. She picked up one of the vials and read the label.
'XENOMORPH RETROVIRUS'
Penny didn't have a clue what xeno, morph, or retro meant, but she had a pretty good idea what a virus was. She went to put the vial back in its holder, but it accidently slipped out of her hand and shattered on the floor. Some of the dark liquid splashed onto her legs.
"Oh, no," she though, hoping she wouldn't get sick or something. She looked down at the spill. "I better clean that up." She got a towel and hurriedly cleaned up the spilt liquid. After it was all cleaned up, she threw the towel in the wash, grabbed the milk that was still in the living room, and went back over to her apartment.
After a few minutes, she started feeling strange. She was suddenly overcome with a feeling of nausea.
"Oh no," she though. "I am getting sick."
Suddenly she felt an odd sensation in her right hand. Looking down at it, she saw in horror that her fingers were stretching out and becoming bonier. The skin on her hand was also hardening and turning black.
Penny screamed in horror. She then found that the same thing was happening to her other hand and both her feet. The changes slowly began to creep up her arms and legs.
She then felt a twisting pain in her tailbone. She could feel something pushing against the inside of the back of her shorts. Her shorts and her panties ripped apart as a black, boney tail grew out of her backside.
Her shorts and panties now lying in tatters at her feet, Penny fell onto her hands and knees, her entire body burning in pain as her insides started changing and rearranging themselves. "W-what's happening to me?" she thought out load.
She began to grow, her entire body becoming larger by the minute. As this happened, she felt two bulges in her skin just below her breasts. Then two bug-like arms tore through the skin. She found she could move them.
Then she felt a weird sensation coming from her loins. Looking underneath her, she saw a slimy, yellowish, tube-like mass push out of her vagina. It continued to grow larger and larger behind her along with the rest of her body.
Her top and braw ripped apart from the stress of her growing body and fell off her. Now completely nude, Penny felt her head begin to change. Her teeth fell out and were replaced by sharp predator fangs. Her tongue rearranged itself in her mouth and hollowed out and hardened into a tube. A second pair of jaws grew at the front of it.
Penny grunted in more pain as her head began to stretch out in the front and the back, her human skin tearing and falling off, revealing new, black, hard skin underneath. A large, sleek, exoskeletal crest began to grow out of the back of her head and her face morphed into that of an alien monster's. Penny tried to curse, but all that came out was an animal-like noise.
Penny's human thoughts began to fade, being replaced by new, primal instincts. Penny fought to keep her mind, but it seemed the more she struggled, the faster her mind became more animal.
As her body continued to grow, her arms and legs changed shape became more bug-like. Her breasts shrunk and shriveled to nothing and the skin on her torso tore open as spines and spikes grew out of her back, leading down to her now long, scorpion-like tail.
The last of Penny's human thoughts faded away as her body completed its changes. She pulled off the last clinging remains of her old human skin and got on two feet. She had to duck her now massive head to keep from hitting the sealing.
She turned her head to look at her massive ovipositor, stretching out behind her across the apartment. She felt a growing feeling in the giant sac-like structure and instinctively began to push. Slowly, an egg slipped out of the opening at the back of the ovipositor and landed softly on the floor, covered in birth slime. Penny felt a sort of pride in the egg she had just laid. She soon felt another one inside her ovipositor, slowly approaching her birth canal. She got ready to lay that one to, and all the ones that would follow. She accepted her knew life with a contented hiss. She was the queen.