marine creature vs sea animal

marine creature and sea animal both are nouns.

Word	Noun	Adjective	Verb	Adverb
marine creature	Yes	No	No	No
sea animal	Yes	No	No	No

As nouns, marine creature and sea animal are synonyms defined as:

marine creature and sea animal: any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals

Other synonyms of marine creature include marine animal, sea creature.

marine creature (noun)	sea animal (noun)
any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals	any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals