I don't know how rare but he's a picture of our horseshoe crab. Its right after he molted.
This picture is from my reef tank 12 years ago. I was going through my old phone and found this picture of Loard Helmet our horseshoe crab. We had him for 5 or 6 years before we got out of the hobby and gave everything to a lfs. I had started a business and we were moving so no time for a tank. Now I'm building a new tank and after looking for old pictures I thought I'd share this one. It's his molt and him in the background.
He was a destroyer of bristle worms. He would cruise the sand bed and destroy worms and flip over anything in his way. We bought him on a whim and didn't regret it at all. Hopefully he's still around somewhere.
Everything I put in the tank LOL he is a little piggy. I feed him brine, micro pellets and flake. But he will try and eat mysis and anything else I toss in for the other fish. @sky414
Gunther's wrasse (Pseudolabrus guentheri), it's not very brightly coloured and it's not found in deep waters off japan... but it's probably still rarer than what 99% of 'rare' fish are! It's endemic to the subtropical waters of eastern Australia. This guy is an absolute beast too and is not scared of any other fish.