Baby hippo and mama. The hippopotamus' name literally means "river horse," even though they are more closely related to whales and dolphins than other animals. It can submerge for 5 minutes under water, and run on lands at speeds near 20 miles per hour. It holds the record for largest open gate mouth of any land animal, and is the second largest on land. It is responsible for many human deaths every year and is a highly aggressive and feared animal.
Baby bats. Without certain types of bats to take care of a large selection of insects, parts of the world would be overrun by bugs. Fruit bats are necessary in the eco-system to propagate fruit crops. Just sayin'