least weasel vs stoat

least weasel

noun
  • The common weasel, little weasel, or simply weasel (Mustela nivalis), the smallest member of the weasel genus Mustela, native to Eurasia, North America, and North Africa. 

stoat

noun
  • Mustela erminea, the ermine or short-tailed weasel, a mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip. 

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