Yeah I put a few fish in with mine and he doesn't sleep until he annihilates them. One time he ate the Barbs I put in with him but left the face of one, I think it was a warning to the others.
I'll be getting a Dragon soon, I may get an Arrowhead eventually. Do me a favor and tell me if this link works, I have videos of my puffers up here-
Www.youtube.com/lymitliss