i have a greenspotted puffer
and from my experience, they don't mix too well with my all too curious cichlids or at least central american ones, also mine has not done well with mollies, guppies, or my dragonfish goby (which he tore to shreds is lucky to have lived from the experience). i have also read that they don't do well with each others. right now i have mine in a ten gallon set up by itself (b/c he just can't behave). it is kind of amusing to feed it worms, and they are an interesting fish to watch, so i guess if that is what you enjoy they are an ok fish, i don't completely hate mine, i simply don't dare to risk throwing money away to feed him extra special fish snacks (pieces of dempsey, jewel fish, pacu, oscar, ect.), he is alright other then that but i have to admit i hold a grudge b/c he tried to eat some of my favorite fish.....