hobbit vs imaginary creature

hobbit and imaginary creature both are nouns.

Word	Noun	Adjective	Verb	Adverb
hobbit	Yes	No	No	No
imaginary creature	Yes	No	No	No

As nouns, imaginary creature is a hypernym of hobbit; that is, imaginary creature is a word with a broader meaning than hobbit:

hobbit: an imaginary being similar to a person but smaller and with hairy feet; invented by J.R.R. Tolkien
imaginary creature: a creature of the imagination; a person that exists only in legends or myths or fiction

Other hypernyms of hobbit include imaginary being.

hobbit (noun)	imaginary creature (noun)
an imaginary being similar to a person but smaller and with hairy feet; invented by J.R.R. Tolkien	a creature of the imagination; a person that exists only in legends or myths or fiction