That's inevitable with CTs, he's just getting started. Wait until the Undulated gets a little bigger. I can, in time, see these two triggers shredding every fish you have, then starting in on each other. Neither the CT or the UT make decent community fish. That poor puffer won't be able to get a second away from them, once they find how slow & vulnerable he is. Having these fish together while small is a problem, as they grow, it will become impossible. Did you do any research on the Ct & UT? IMO & IME, the only fish that do well (long term) with Clown or Undulated Triggers are big, bossy fish that can get away from them when they need to. Most belong by themselves in species tanks, especially an adult UT. Crowded tanks, like this, are just big smorgasbords for these fish. IMO & IME (I've seen it happen): that CT could go postal anytime now and you could come home to a real disaster Some Asian fishkeepers cram fish into bare tanks to equally distribute the aggression; but, I can never remember a CT or UT in the videos of those tanks. (Charlie Sheen, a few cases of scotch, and a few hookers suddenly come to mind).