AWESOME fish! my favourite freshwater fish! mine was a monster! lol...if introduced small they will mix with malawis, but be VERY cautious as these are HIGHLY aggressive! mine would attack me through the glass! and cleaning time was fun too!
although as a rule they (mostly) leave fish smaller than themselves alone as they dont see them as a threat.....but still have their off days where they may decide to cull a few malawis off lol...