This is not a unique form of coral or a bizarre sea anemone - They are rubber creatures made out of balloons

For me it looks like a sea anemone embedded in the coral but I am always thinking about water. I found this originally at NotCot where DesignBoom is featured and gets the credit!

From Desing Boom: "...Like the pop artists of the late 20th century, artist Jason Hackenwerth transforms common materials and imagery into something new. Hackenwerth’s material of choice is balloons. he blows up hundreds of balloons and strings them together in unusual forms to create artwork that resembles an array of
strange animals, insects or aliens. ..." [Link]