Beavers (and Fallen Hollowed Logs)

With the Dappled Forest biome coming and older ideas like shelf mushrooms returning with it, a perfect way to bring back the hollowed logs from the Wild Update concept art would be to add Beavers as a docile mob that inhabits the forest. They would chew on fallen Poplar trees, taking the wood to build dams near rivers, leaving behind hollowed logs that could maybe be used to craft Tree Bark, which could be an alternative way to craft paper, or could even be combined with hay bales to craft the Straw Bed.