Sonder is an amphibious creature that becomes more aquatic as it grows. A young Sonder has a buoyant, feathered body that floats on the water's surface. As it ages, it grows soft fins that help it swim under water and explore the depths of the sea. At this point, its eyes also start to look at each other and appear to communicate. To keep your Sonder happy, make sure to give it lots of intellectual stimulus. They like to read books and explore the world.