The Moon Crabs

An astronomer named william henry pickering suggested that moon bison could be migratory animals. The creatures would need to have a hard outer shell, lest their insides become their outsides in the extremely low gravity of the moon. Their eyes would getatheir energy by a sunlight, sort of like a buggy photosynthesis,. And they also would use acitic secretions through little appendages under their shell to pull all this stuff out. But we're not even at the best part yet. They'd apparently be able to get trace water from the surface and things below the surface.