Original: The Malacostraca ( Greek : '' soft shell '' ) are the largest class of crustaceans and include most of the animals that non-experts recognize as crustaceans , including decapods ( such as crabs , lobsters and shrimp ) , stomatopods ( mantis shrimp ) and euphausiids ( krill ) .
Simplified: The Malacostraca ( Greek : '' soft shell '' ) are the largest subgroup of crustaceans . They include decapods ( such as crabs , lobsters and shrimp ) , stomatopods ( mantis shrimp ) and krill .