hermit crab
['thimble', 'alligator lizard', 'acorn', 'tiger shark, Galeocerdo cuvieri', 'platypus, duckbill, duckbilled platypus, duck-billed platypus, Ornithorhynchus anatinus', 'pick, plectrum, plectron', 'horned viper, cerastes, sand viper, horned asp, Cerastes cornutus']