sea animal vs sea creature

sea animal and sea creature both are nouns.

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

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

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

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

sea animal (noun)	sea creature (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