Merriam-Webster Collegiate Dictionary - echidna

 noun  Etymology: New Latin, from Latin, viper, from Greek — more at ophitic  Date: 1832 a spiny-coated toothless burrowing nocturnal monotreme mammal (Tachyglossus aculeatus) of Australia, Tasmania, and New Guinea that has a long extensible tongue and long heavy claws and that feeds chiefly on ants; also a related mammal (Zaglossus bruijni) of New Guinea having a longer snout and shorter spines