Three parts.
1.) Multi-tile creatures.
2.) Platforms that can be built and put on large creatures' backs (as, say, an archers' platform).
3.) The ability to build structures on such platforms.
Why?
Simple.
Let's say that, after these things have been added, I mod in big, 3X5 or 5X5 flying sharks (maybe bigger?), like whale sharks but with great white shark heads. I bring a breeding pair on an embark, along with a miner, two siege engineers/operators, a mason/carpenter, a woodcutter/herbalist...uh, mostly a normal embark.
I set up camp. No military, no problem. I give my engineers/operators a siege workshop or two and send them to terrorize the cavern wildlife with waste rock from the mines.
Meanwhile, the mason(s) make a couple howdas for the flying sharks-ones big enough to cover the whole back. I give the catapulters a break and tell them to put a ballista (can't spell it) on the front of the howdas and to strap them on.
A few years pass. Migrants arrive, nobles die, elves drown after getting angry at a wooden bin, a new broker is selected. Life goes on.
Then, one spring day much like any other...
A vile force of darkness has arrived!
[size=9]Curses! The goblins have learned of the fort's underguarded riches![/size]
The caravan is butchered instantly;thank Armok the elves brought nothing more valuable than cloth and wood harps. A woodcutter dies after taking a goblin wrestler with him; his family is jailed for vandalizing the dining room. Civilians are ordered to stay within the halls; with no reason to do so, they shrug and find their deaths in a cavern.
The military was butchered in the courtyard, but the trolls could not bash down the mighty drawbridge that sealed the civilians inside the mountain.
The siege drew on.
The days turned to weeks, and then to two months.
All was quiet.
It was a normal day for the siegers. Gather plants, fend off the trolls, play dice, fire off shots at dwarves who were messing about in that alcove up in the mountain. Nothing special...
Yet.
[size=10]Suddenly, a roar like the carp of old, with the strength of the modern elephant, echoed across the valley.
The siege drew silent. A troll bookkeeper stopped yelling at its goblin "keeper." Some others looked up from their crude dice game of "see how hard I can throw the dice at you."[/size]
[size=14]suddenly, two great skysharks tear out of the alcove. A third and fourth follow, progeny of the first. The troll drops his pen and rushes for the gates. The goblins change their game to "see how hard I can throw the dice at the skyshark while grabbing my scourge." The goblins run, in fear or for their weapons. Most in fear, as their siege leader is dead before the skysharks come within chomping range.[/size]
[size=15]Yes, the goblins have run afoul of the most terrifying weapon in the dwarven arsenal that cannot set the alcohol on fire:[/size]
[size=20]Giant sharks with frickin' BALLISTAE attatched to their heads![/size]
[size=18]Which they made in a CAVE! With a bunch of ROCKS![/size]
And memes.
What do you think? Awesome, crazy, or never-gonna-happen?
(All three is acceptable.)
Also, what on earth is wrong with those last few sizes? The really huge ones are tiny normal-sized, the little ones are huge...it just messes everything up. Bet it'd look great if it wasn't for that.
The artist's lament.