coral {noun} /ˈkɒr(ə)l/

a hard stony substance secreted by certain marine coelenterates as an external skeleton, typically forming large reefs in warm seas.

a sedentary coelenterate of warm and tropical seas, with a calcareous, horny, or soft skeleton. Most corals are colonial and many rely on the presence of green algae in their tissues to obtain energy from sunlight.

plus underwater antlers, of course.