doggo vs yellow dog

doggo

noun

  • A dog. 

adv

  • Only used in lie doggo. 

yellow dog

noun

  • A Carolina dog. 

  • An item or person of low value. 

  • Used other than figuratively or idiomatically: see yellow, dog. 

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