mutant vs fauna

mutant and fauna both are nouns.

Word	Noun	Adjective	Verb	Adverb
mutant	Yes	Yes	No	No
fauna	Yes	No	No	No

As nouns, fauna is a hypernym of mutant; that is, fauna is a word with a broader meaning than mutant:

Other hypernyms of mutant include animal, animate being, beast, brute, creature.

mutant (noun)	fauna (noun)
an animal that has undergone mutation	a living organism characterized by voluntary movement
(biology) an organism that has characteristics resulting from chromosomal alteration	all the animal life in a particular region or period

mutant (adjective)	fauna (adjective)
tending to undergo or resulting from mutation