Terrestrial crabs are land-dwelling crustaceans that primarily inhabit coastal areas, forests, and mangroves. Unlike their aquatic relatives, these crabs have adapted to life on land by developing specialized gills that can retain moisture, allowing them to breathe air. They are often found near water sources, as they need to keep their gills wet to survive. These crabs exhibit a variety of sizes and colors, with some species, like the Coconut Crab, being the largest terrestrial arthropod. Terrestrial crabs play important roles in their ecosystems, helping to aerate the soil and recycle nutrients through their feeding habits.