i know they can be mean, i have been watching him for several weeks(9 1/2) at the lfs, and so far he is doing good. i will watch him a while longer(maybe 2 months) and if he does one thing mean i wont get him. but he has been kept with, in the time i have been watching, green terrors, oscars, jd's, a frontsa, some convicts, and all but the oscars where at least 1/4 of his size.