Would be nice to see a mob with missile containers capable of preforming the roar twin airstrike attack. It would be limited to mid-long range only, in a 90 degree feild in front of the monster. They would be smart enough to strafe around the target as opposed to just chase it. This would add in a mob that cant be defeated as easialy by walking backward and shooting, that instead is better defeated by going towards it instead of away.

It would also have the abillity to fire the missiles over walls, making it unreachable for certain periods of levels. Perhaps you would have to run through the blasts and get past some tankier monsters to hit a ghost block that would erase their cover.