Oscars are like people, every one is difrent so what works for us may not for you. I've had O's in with JD's, cons, FM, and sevrums with no proplems but I've also had "Gluton" my first and meanest O who would let nothing live in his tank, so all you can realy due make sure he cant eat it and hope for the best, provide lots of shelter the O can't fit in and go with somthing that will fight back like a con or a jd.