We have a blue jawed trigger in our reef tank and he leaves all of the corals alone, but has killed every other fish we had in there. He did okay with an eel, but then the eel became too agressive toward us. When we bought the trigger it was in a small tank with other small fish, and was really skiddish, but once he got used to having more room in our tank, he showed his true colors. We love our trigger but can't have any other fish in there with him now. He killed our dwarf lion in a matter of two days, and picked the pajamas off our cardinals in a week. You can buy the most peaceful seeming trigger and they can snap overnight and kill everything.