World's Weirdest - Fish Battle on Land. Now if a fish had evolved over millions of years to live in water, it would be very comfortable there. If it found itself in the dry, it would immediately wither and die from asphyxiation. We've all had a pet goldfish and know how this goes. So why would muscled fins evolve for walking? Why would the first fish leave the water? And what kept the first fish from DYING like my and your poor pet goldfishes?