fauna vs beast

fauna and beast both are nouns.

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

As nouns, fauna and beast are synonyms defined as:

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

fauna (noun)	beast (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	a cruelly rapacious person