Would a Tiger Oscar & a Jack Dempsey fish get along?

ONLY if the tank is over 120-150 gallons - the Oscar will get about 8"-10" in a year, the JD will grow at a similar speed. They are both territorial, nothing semi about it, and if they don't have space to keep away from each other they'll pull each other to bits - especially if you wind up with 2 males (Oscars cannot be visually sexed).