animal vs fauna

animal and fauna both are nouns.

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

As nouns, animal and fauna are synonyms defined as:

Other synonyms of animal include animate being, beast, brute, creature.

animal (noun)	fauna (noun)
a living organism characterized by voluntary movement	a living organism characterized by voluntary movement
	all the animal life in a particular region or period

animal (adjective)	fauna (adjective)
marked by the appetites and passions of the body