I had one for about 2 years - got him tiny, moved him about a few displays. Then we put him in our 1000 gallon - he was the smallest fish at the time, and the last. Model citizen for 8 months. Then, one day, he attacked my Batfish - largest fish in the 1000g. Tore out the Bat's eye. Was trying to get the other when I intervened (removed the Bat - couldn't catch the trigger right away).
Fortunately the Bat healed - lived another 5 years with one eye - many of you will remember Bruce the Bat. The Trigger was later sold (with full disclosure of his attitude) to someone who keeps sharks. He even gave the sharks a hard time.
Meanest fish, EVER.
Jenn