Tom stared with disbelief. Something strange was going on here. His mother had always been a petite woman, even more so when that nasty fever caused her to loose a lot of weight. But now she was the same height that he was. "What, what are you looking at?" asked Mrs. Baker.
"Mom, you're...you're growing," said Tom.
"What are you talking about? My pajamas are just tight," said Mrs. Baker. Tom noticed with some embarrassment that the pajamas were getting constantly tighter, contorting around her body shape. And she was looking a lot more solid than she had been before.
"But Mom, you're taller than me," said Tom as he noticed his mom was gaining more height.
"You're just looking at me from a different perspective. I'm just-" started Mrs. Baker when there was a snapping sound and Tom felt something ping off his shoulder. They looked down to see that Mrs. Baker's breasts had swollen a lot larger than they usually were. She had never been bigger than a B cup, even when she was pregnant. But now she was easily a C cup and her breasts were enlarging before their eyes, straining the other buttons that looked ready to pop. "What...what is this?" asked Mrs. Baker as she cupped her larger bosom.
"Uh...I think I better call someone," said Tom, trying to not stare at his mom's rack.
"Who are you supposed to call about this?" asked Mrs. Baker, "People just don't get bigger." She lifted one arm and flexed it, her pajama sleeve starting to tear around her growing muscle. "But then again, this isn't so bad so far," she said, "I'm feeling better than before." That's when she noticed Tom staring again. "Now what?" she asked.
"Your face is...swelling," said Tom. Mrs. Baker frowned before walking over to the mirror. Halfway there, her steps started to fumble. For some reason, she was picking up her ankles higher than she ought to. When she looked at the mirror, she could see she had the body of a fitness body, a well-stacked one at that. But then she noticed her lips were swelling out more and her nose was starting to flatten. That's when she noticed her ears were bigger and changing shape. She looked at her hands and noticed the fingernails were getting darker and white hair was starting to appear on them.
"Tom, what's happening to me?" she asked in confusion before she felt some discomfort over her butt. Tom had a clear view of his mom's butt starting to outgrow her pajama bottoms into something a lot more plush. He could also see the tendril of flesh extending above it, growing longer and growing white hair. She felt her new limb with one hand before reaching up and feeling the bumps that were forming on her head. "Am I turning into a cow?"
Tom hadn't wanted to say it, but his mom was starting to look a lot more bovine. As her pajamas ripped, more white hair was revealed. Her bare feet had altered a lot, growing longer as her toes started to fuse into one black mass. Tom could see his mom's ears growing longer and more floppy as a pair of horns started to push their way out.
Mrs. Baker watched as her face extended out into more of a cow muzzle. Her pajamas were ripping up, exposing almost all of her underwear which were getting awfully tight against her bigger butt and her humongous breasts. With a loud rip and snap, both top and bra gave way, allowing her 'udders' to bounce free. Mrs. Baker yelped before covering her nipples. She was only half-surprised when she felt a wetness. In the mirror stood an anthro cow covered in white hair except for the hair on her head and the brown tip on the end of her tail. True, she was curvier and more muscular than she ever was, but she was a completely new species too. "How did this happen?" she asked.
"It must be the milk," said Tom, "Oh great, what if Mr. Darcy gave it out to more people. I better call him." He hurried out of his mom's room, leaving the cowwoman by herself.