They can look beautiful or creepy as hell, depending on what you are expecting and what they are doing. Sitting still they look like a very delicate coral, almost like a flower. They are cool to watch swimming, but that can be a shock at first if you aren't expecting it.
A Feather star is not the same thing as a starfish although they are related. A starfish moves around with it's tube feet and arms. A feather star and sea lily are attached to the ocean floor kind of like a sea anemone or coral. I was going to say a feather star or sea lily of some sort.
Three years ago my wife and I caught over a hundred of those on a string of pots. It was really strange - we had a great set with pots full of shrimp, so we tried to set back on nearly the exact same spot. The next pull did not yield one shrimp - not a single one - but every pot was absolutely covered in feather stars - probably 10-20 per pot. Strangest thing I've seen yet while shrimping, and only that one time.
Crinoid is the proper name of the Class of ~600 species that includes feather stars, exactly like Mammal is the proper name of a Class that includes dogs and humans. So, all feather stars are Crinoids, but not all Crinoids are feather stars.