creature vs organism

creature and organism both are nouns.

Word	Noun	Adjective	Verb	Adverb
creature	Yes	No	No	No
organism	Yes	No	No	No

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

creature: a living organism characterized by voluntary movement
organism: a living thing that has (or can develop) the ability to act or function independently

Other hypernyms of creature include being.

creature (noun)	organism (noun)
a living organism characterized by voluntary movement	a living thing that has (or can develop) the ability to act or function independently
a living being	a system considered analogous in structure or function to a living body
a person who is controlled by others and is used to perform unpleasant or dishonest tasks for someone else