Mofumofu to Mukumuku to Isekai Hyouryuu Seikatsu

Kentaro Yamada, an office worker, lived a peaceful life with his dog, Max, and his cat, Nini. One day, he had an accident while out for a walk and woke up to a spectacular natural landscape. Suddenly, a squirrel-like creature, the self-proclaimed "Creator," appeared and said that they were in another world. He said, "Thanks to your coming here, this world has been saved!" and that we could live freely.
With that explanation that he didn't quite understand, Kentaro Yamada ended up living in a medieval fantasy, RPG-like world, with fluffy, chubby, and precious friends. He became a cheat monster-using savior, together with Max and Nini, who grew to giant sizes and could suddenly talk!

Official JP: Comic Earth Star, Official channel of Comic Earth Star in Nico Nico Seiga

Original webnovel: Shousetsuka ni Narou