Charlie, prior to having been swapped with humans, was just a 2 year old heifer living on a farm, before becoming an 18 year old that's part of a family of four inside Jeff's old house. She happened to be a bit of a tomboy, as she liked having her hair cut short and wearing more male clothes rather than more effeminate sets of clothes. Her vast array of video games (which once belonged to Jeff), were things she loved to persue every once in a while. Thanks to the role swap, instead of Jeff having been the one to order the Chronivac, Charlie now was the one who bought it.
"Now that I have this thing on my PC, I wonder what I should try doing first?" Charlie pondered about what she could do and there was so much she could do. Unlike Jeff who was focused on living a new life, Charlie was happy with her life but wanted to mess with other people's lives more. "Hmm, perhaps I should see if I can mess with people at school."
Using a little bit of ingenuity, Charlie managed to get the Chronivac to install onto her phone. Using the now Chronivac app, she had a lot of plans to mess with people at school thanks to the Chronivac app, especially against some of the school bullies such as Sarah. Sarah was someone who Charlie butted heads with a lot, and typically due to Sarah's popularity and being on the cheer squad, Charlie was usually the one who got seen as the outcast. But now with the Chronivac, things are equal.
"Just you wait Sarah, you and those big udders of yours will be gone and soon you'll be at the bottom of the high school cow hierarchy." Charlie mumbled to herself before setting off to school to plan her revenge against the popular cow.