Walking Fish

Walking fish, sometimes called ambulatory fish, is a general term that refers to fish that are able to travel over land for extended periods of time. The term may also be used for some other cases of nonstandard fish locomotion, e.g., when describing fish "walking" along the sea floor, as the handfish or frogfish.

The Mexican walking fish isn't actually a fish, it's a salamander. They're also closely related to frogs and other amphibians. They share many of the same characteristics, including a three-chambered heart.