we have 3 pea/dwarf puffers and at first we only had one and wanted to see if it would be okay in with 3 panda cory, 2 ghosts and a hujeta gar, well it was fine.. at first. It waited until we turned the lights out to go to sleep (they watch you just as much as you watch them) and when we woke up everything was missing chunks of their fins except the puffer, needless to say it is in a species only 10 gallon with 2 other peas, they are quite aggressive and just because they look like they are fitting in at first they might not be lol. and i've heard peas are supposed to be less aggressive than other puffers so I'm not sure