(1):

(n.) A North American aquatic fur-bearing rodent (Fiber zibethicus). It resembles a rat in color and having a long scaly tail, but the tail is compressed, the bind feet are webbed, and the ears are concealed in the fur. It has scent glands which secrete a substance having a strong odor of musk. Called also musquash, musk beaver, and ondatra.

(2):

(n.) The musk shrew.

(3):

(n.) The desman.