Well that didn't turn out too well. I put the fancy in with the mocha and the mocha grabbed him by the tail and started spinning him around. They're both juveniles, by the way. I separated them, then a minute later the mocha did it again. I broke it up and watched them for about 20 minutes. He kept taking an aggressive stance to the fancy so I took the fancy out, since he cost me a pretty penny. Maybe I'll try again after work since I'll have more time to introduce them.