UM, ducks, geese. Its mostly mammals that live in water.
walrus
Technically they have flippers.
an ocean mammal with flippers
flippers
Platypuses have just four feet. They do not have flippers.
Penguin feet
Flippers.
Flippers
Flippers
They have webbed feet to help them swim.
yes
Dolphins have flippers because they are useful for navigating in water. Since dolphins live their whole lives in the water, they do not need feet. Flippers are useful for steering.