One is a large, or should I say huge, green brittle star. The main body is about 3" in diamater. Legs are at least 6" long each.
I've also got a black one. Not as big, but on the large side. I haven't seen it in a while so I'm not sure exactly how big it is.
If you want them, let me know. If you want to trade some corals for them because you feel bad about taking free stuff, I'm fine with that too.