The Shell Walker

The Earth's surface has become a wasteland. Mountain-sized giant snails serve as humanity's last arks—their shells shield people from death, yet trap billions inside, starving and choking on poison gas as they await digestion by the colossal snails. Until Lu Yun discovers a mysterious green sprout within his body—capable of devouring anything and evolving infinitely. He will shatter this prison shell and find his way home.