remora vs viper

remora

noun
  • A serpent. 

  • Any of various elongate fish from the family Echeneidae, the dorsal fin of which is in the form of a suction disc that can take a firm hold against the skin of larger marine animals. 

viper

noun
  • A venomous snake in the family Viperidae. 

  • A dangerous, treacherous, or malignant person. 

  • A person who smokes marijuana. 

  • Any venomous snake. 

How often have the words remora and viper occurred in a corpus of books? (source: Google Ngram Viewer )