trilobite
['grasshopper, hopper', 'platypus, duckbill, duckbilled platypus, duck-billed platypus, Ornithorhynchus anatinus', 'lionfish', 'amphibian, amphibious vehicle', 'hen-of-the-woods, hen of the woods, Polyporus frondosus, Grifola frondosa', 'slide rule, slipstick', 'porcupine, hedgehog']