Funny. One of the things that caught my curiosity about them was the fact that they were very docile and several prepare claimed to have no issues with them in a reef tank with inverts. Right now I have a green spotted in a nano tank. He barely an inch but he hasn't had any issues so far with the link coral I've put in there as well as hermit crabs, ghost shrimp, a peppermint shrimp. Of course even the smallest hermit is bigger than he is and the shrimp have been chased but have also done some shading. He also hasn't bothered the wild tube worms or tube snails on the live rock. Maybe I am feeding him too well. I tried giving him snails but he ignored them unless I crushed them first. I realize it's probably his age but I've seen a few posts about green puffers in reef tanks too. If they kill anything it's usually the inverts but seem to ignore coral which I am fine with. Only inverts I use in my main tank now are ghost shrimp which can double as food. Reason I'm intereated in the figure 8 is that they are supposed to be far more docile.