sea urchin
['harvestman, daddy longlegs, Phalangium opilio', 'platypus, duckbill, duckbilled platypus, duck-billed platypus, Ornithorhynchus anatinus', 'wombat', 'nematode, nematode worm, roundworm', 'American lobster, Northern lobster, Maine lobster, Homarus americanus', 'croquet ball', 'Arabian camel, dromedary, Camelus dromedarius']