There are a number of animals that live in the water but are able to walk on land. Many of these animals have cutaneous respiration. Cutaneous breathers have highly vascularized skin, rich with blood vessels that are able to absorb oxygen in the air. Some semi-aquatic animals have large lungs, allowing them to spend a large majority of their lives on the water, while still being able to traverse on land if need be.
The hippopotamus - commonly dubbed as the "hippo" - is a semi-aquatic mammal that lives in Africa. Closely related to whales, the hippopotamus can spend up to 16 hours wallowing in the rivers and lakes of the sub-Saharan deserts of Africa. They feed, breed, and stay cool in the water. They are also capable of walking on land with their short, stubby legs.
Crabs are crustaceans that can be found in all the world's ocean, with many species being able to walk on land. From the size of the Pea Crab, which can grow a few millimeters long, to the Japanese Spider Crab that can have claws that can grow up to 12 feet long, crabs come varied shapes and sizes. Crabs are able to walk on land, with crabs in the Gecarcinidae family adapting a highly terrestrial existence. Crabs in the gecarcinidae family have evolved to have a set of gills that are able to absorb oxygen, enabling them to walk on land for short periods of time.
Mudskippers are fish that are able to walk on land with their pectoral fins. Found in tropical waters, mudskippers are able to swim, as well as being able to feed and defend territory on land. Mudskippers gained their name for their ability to "skip" and "hop" on land, making them highly mobile. Mudskippers are cutaneous breathers, absorbing oxygen through their skin and mucous. Since their ability to absorb oxygen is facilitated through moisture, they are often required to stay within the confines of humid or wet land.
Amphibians like frogs and salamanders are able to walk on land, if need be. Mostly found in and around freshwater, amphibians are able to absorb oxygen through primitive lungs, as well through cutaneous respiration. To enable cutaneous respiration, their skin needs to be constantly moist. Amphibians are able to venture short distances from water to hunt.