Castorocauda was a semi-aquatic mammal from the late Jurassic. Its head and torso resemble a other but, its tail and feet resemble that of a beaver. Yet this mammal is not related to either the weasel or rodent family but instead to a dead mammal linage. Its main food would be fish, which they hunt in the water. There bodies where small and nimble so they can escape large predators. Once cornered this mammal would release a horrible stench that is designed to hit the predators eyes, or mouth.