sea creature vs animal

sea creature and animal both are nouns.

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

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

sea creature: any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals
animal: a living organism characterized by voluntary movement

Other hypernyms of sea creature include animate being, beast, brute, creature, fauna.

sea creature (noun)	animal (noun)
any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals	a living organism characterized by voluntary movement

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