Decapods have ten legs. The last five pairs of appendages on their thorax are walking legs. In some species, the first pair of walking legs has large pinchers or chelipeds.

Decapods have three pairs of appendages, or maxillipeds, on their heads that make up their mouthparts. They also have two pairs of antennae on their heads. Crabs, shrimp, krill, crayfish, and lobsters are all decapods.