Mokosh is the Russian Goddess of the Earth, known from the old Kievan pantheon; She is likely a form of the ancient Mati Syra Zemlya or 'Moist Mother Earth', and like Her associated with water, Her name coming from a root meaning 'moisture' or 'wetness'. She is also a Goddess of weaving and spinning. There is a traditional Russian embroidery pattern showing a stylized woman standing between two horsemen that is thought to be Her; on such She is often shown with arms upraised holding a pair of birds.
She is in the traditional Russian outfit of a sarafan, or loose cone-shaped dress, worn over an embroidered blouse. I've put a horseman on each sleeve, so She is in the same position as in the embroideries. She wears a traditional Ukrainian flower headdress called a vinok, here with wheat, poppies (which commonly grow among the wheat), and blue flax flowers (the blossoms of the plant from which linen is made). She wears golden temple ornaments (those odd gear-shaped thingies) and long flowing blue ribbons that with Her necklace and earrings symbolize water. The background is after traditional Russian folk painting.