Beaver

Among the most iconic characteristics of the beaver is its massive set of teeth, which it uses for its most iconic activity: gnawing down trees to build its river dam home. A beaver can fell a tree half a foot wide within an hour and bring down even larger trees if given enough time. The beaver's stalky muscular frame allows it to lift and drag heavier loads than its size would indicate, and the industrious creature can quickly amass large quantities of lumber at the site of its new home.

Using a combination of gnawed wood, stones, and hard mud, beavers create dams capable of housing large families. These dams can be modest 10 foot long structures or massive feats of engineering reaching over 300 feet long. The dams are quite resilient and can only be entered via underwater tunnels. Beavers are also diligent about repairing and maintaining their homes, using their keen hearing to detect leaks in need of patching.

Besides humanoids, no creature does more to shape its environment than the beaver. The dams beavers create can alter the paths of rivers, reshape lakes, and create new ponds. These effects are often a boon for their ecosystems, but beavers can also be a bane upon environments that aren't suited to their deforesting and river-altering tendencies. Beaver dams can also result in the sudden flooding of humanoid settlements.