Coral Friendly, even does great with a clam. Tamer has had one from a juvi and now i am guessing he is around 10"? Louis had him in his shop for a while with all of his corals. The only one I never tried was a brain. I have had mine over a year, got him from CB pets as a juvi.( He is in my gallery, I need to update his picture) I have tried two Red Sea imperators before this one, none of them made it over a month. Sorry but the articiles that state Red Sea are more hardy is questionable? I had one about twelve years ago when saltwater was new (to me) and all I had to feed him was brine shrimp. I had him in a trigger tank with the nitrates above 60. And I managed to keep him for three years until I gave him to a friend. The tank Jr. is in now is 155 but by tomorrow night I hope to have him transfered to my 200. If you get one please buy one from someone who will hold him for a while to make sure he is eating and healthy. I try to support all of the fish shops(ask my wife) in the SA area but when it comes to this fish this one was my achilles heal. They like to hide a lot, so have plenty of tunnels and structures for him to feel secure around. The fish foods on the market now are excellent. The one I had twelve years ago never changed, the one I have today went from three to five inches in a year and went from a clear juvi to adult colors. Good luck on your endeavor.