eager beaver vs tiring

eager beaver

noun
  • One (especially a child) who is very excited or enthusiastic to begin a task; a person who is exceedingly assiduous in an enthusiastic manner 

tiring

noun
  • Bits of bone and tough organic material from a corpse given to hawks to abate their hunger. 

  • The action of tiring. 

adj
  • That tires or tire. 

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