This sea dragon has strangely shaped fins to make it look like a piece of sea weed or kelp

Amazing creatures. Considered highly endangered because they live only in one area on the Great Barrier Reef. A third species was recently discovered!
Only one man in the world is allowed to collect them, and they cost around US$10,000 per specimen.

I went diving for the first time this summer and my mentor showed me several corals and sponges and let me touch them (very soft). After a while she picked up a brown stick. I was just assuming it was another kind of sea plant but suddenly it curled around her finger and it turned out to be a sea horse.
I have never been more amazed by nature in my life.