The animal you are referring to is the kangaroo. Kangaroos are well-known marsupials native to Australia and are known for their hopping locomotion. On land, kangaroos primarily move by hopping and use both hind legs together, propelling themselves forward with powerful jumps.
However, when kangaroos are in the water, they exhibit a different mode of locomotion. They can swim by using their hind legs independently, similar to paddling or kicking. Each hind leg moves separately, allowing them to propel themselves through the water using alternating kicks.
This ability to swim and use their hind legs independently in water is an adaptation that allows kangaroos to navigate through aquatic environments more effectively. While kangaroos are not known as proficient swimmers compared to aquatic animals, they can use their unique hind leg movements to move through water when necessary.