i know what you mean. everyone that warned me about them never even had one. i know they are aggressive but not as aggressive as everyone says they are. it is a a general assumption most people have on these fish. because of books and word of mouth. i kept one in a 20g and watched his aggression closely he never even touched a damsel that was already in the tank. at my other post an undulate was in a tank with coral. this is just my two pennies