Reading different things online and through his own imagination. Jeff had a single idea on what he wanted to do with the world. Through on single fetish, his wish would be granted by the Chronivac.
Jeff was both a furry and closet nudist. He loved to walk around naked whenever no one else was looking and he furthermore loved to act like a pet. He didn't like the huge, heavy pursuits that some furries wore, but he did like to act as a pet.
With the power of the Chronivac and his own ego, he decided on a simple change in concept for the entire world to undergo. He changed the role of humans to act as a few different domesticated animals(dogs, cats, birds and so on), and those animals to act as intelligent humans.
The results of this would make those animals walk bipedal and have thumbs, while also wearing clothes and being able to speak. Humans would lose their ability to speak and make rational decisions, and some other physical changes to fit their new roles. The names of each species would stay the same. Everything but the roles both species take.
This may be a strange change as Jeff would become just a pet, but he felt that he should be like this and this is what the world was meant to be. It would also change many aspects of history and make humans lose their individuality, but it was a worthy sacrifice for the best.
With the changes completely imputed into the Chronivac, Jeff sat back as the changes commenced.