Translator from Another World, My Pet Is a Golden Cat.

The "half-human, half-tree" boy who came back from the dead unlocked the password to practice by understanding the fancy rants of cats and dogs. In the silent spirit period when thousands of races abounded, he translated the language of beasts into runes of heaven, the wanted criminals into the leader of the beast clan, and the fate of the grassroots into the legend of the continent.