Which organism would be classified as an echinoderm?

The phylum Echinodermata contains organisms that share a specific set of characteristics, including spiny or bumpy skin. There are five different classes of animals in the phylum: starfish, brittle stars, echinoids (which include the sea urchins and sand dollars), sea cucumbers, and sea lilies.

So starfish, brittle stars, echinoids, sea urchins crinoids, sew cucumbers