tiger vs doer

tiger and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
tiger	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of tiger; that is, doer is a word with a broader meaning than tiger:

Other hypernyms of tiger include actor, worker.

tiger (noun)	doer (noun)
large feline of forests in most of Asia having a tawny coat with black stripes; endangered	a person who acts and gets things done
a fierce or audacious person