* River otters: These semi-aquatic mammals have partially webbed feet, which help them swim efficiently.
* Beavers: Beavers also have webbed hind feet, which are crucial for their aquatic lifestyle.
* Platypus: While the platypus is not a placental mammal (it's a monotreme), it is an excellent example of webbed feet in mammals. Their webbed feet help them swim and catch prey in rivers.
* Some species of rodents: There are a few rodent species, like water voles, that have partially webbed feet to aid in swimming.
It's important to note that the degree of webbing can vary within species, and some individuals may have more pronounced webbing than others.
So, while not all placental mammals have webbed feet, several species have adapted this feature to thrive in aquatic environments.