mudskippers - fish that have evolved to live out of water. These fish are completely amphibious, and use their pectoral fins to walk around on land. They have a large gill chamber that retains water and closes tightly when they are not immersed in water.
DIY small cabin retreat: $47K for the land, $10,000 for the cabin. 130 square feet plus a deck - sleeping loft, IKEA furnishings (like a table that folds against the wall when not in use), barn door that opens the inside to the outside. Great little weekend retreat!