Yes, it was I who requested it, and when I saw Aaglo's Stone Giant model I asked if he could do the boulder as a stand-alone unit as well. And many thanks to him, as this is just the sort of thing I needed, and very nicely done! I love the smash.
I got the idea from the Falasha, who appear in the scenario I'm working on. During their frequent clashes with the Ethiopian imperial authorities, they would fight a guerilla war in the mountains, plateaux, and passes of the Abyssinian highlands. They often holed up on a mountain and, as the imperial troops tried to head up the slope to fight them, they would send huge boulders smashing down on them. So I thought this would make an interesting and different sort of weapon. I will make the boulder immovable (so it stays where it is built) and a one-shot only Cruise Missile-style bombard weapon.
I'm now working on a way to incorporate paraplegic unicorn riders into medieval North Africa. It may be tricky but I'm sure it will be worth it.
Thanks again, Aaglo!