yeah- what Milit Said Puffers vary in Viciousness from Figure 8's, Brazilian puffers and Dwarf puffers which are able to be kept in Community tanks if you don't value the other fish highly, throught to ones like the Palamberg and finaly through to ones like the one I have (An Arrowhead) or the Mbu puffer which will hunt down and kill any fish you put in the tank. Finsishing off a full tank of community fish in a couple of nights if its hungry