Just weighing in as I have had a bullhead in the past. They can really be hit or miss. If well fed they most times are ok, but they will snap when things get close, and I always ensure its on the smaller end when compared to the other fish as they can eat some things almost as big as they are. They are also primarily a night predator so maybe transport shock plus bullying? I've had Bluegill with a FL gar but as long as the gar is larger and you give the Blues something to hide in they usually leave em be.
Edit: As a recommendation if your tank is big enough, get a larger Gar than the bullhead (like x2 the length), and if not already put some rock caves for the bullhead on the bottom as Gars rarely go to the bottom of the tank.
Edit: As a recommendation if your tank is big enough, get a larger Gar than the bullhead (like x2 the length), and if not already put some rock caves for the bullhead on the bottom as Gars rarely go to the bottom of the tank.
