Mudworm

Mudworm differs from its ancestor by having much lighter armor that, while leaving it more vulnerable, gives it a lot more flexibility, which helps navigating in complex burrows they dig, along with keen a sense of "smell". Instinctive burrowing behavior protects it from large swimming predators, while giving it access to microbe-rich silt and also leads to better oxygenation of substrate in areas inhabited by P. fodens. Due to living underground, they lost the vivid green pigment of their predecessors, becoming mostly translucent-brown.