okay my first megabeast attacks, its a dragon and it spawns at the northwest corner of my map which thanks to my fortress building will lead it through a relatively narrow gap filled with two cage traps. (its a two square wide gap, the cages are there more for finding ambush parties, than it is a real defense.)
That is if all of the traps had been refilled with cages.
Just prior to the dragon there had been an ambush on my dwarves (if you call it that) in which a lone animal trainer/mason who had just recovered from a spine injury, ran all the way across the map with ambush in tow. I caught two of the gobs in the cage traps, and sicced my champion wrestlers on them (think 4 gobs vs 12 wrestlers) in the process of chasing down the ambush, my champions flattened two snatchers at the same time. It just wasn't the goblin's day.
Well the excitement died down, and I got the cages exchanged save for one. what had happened at the same time, I moved all of my prisoners to the upper floor as I was having problems keeping up with whom I had already stripped of gear. So I had b>j all of my free cages to the area, and was planning to deconstruct the ones not holding a prisoner. So my mechanic only managed to reload one of the traps, and it was on the outside of the turn (meaning creatures will probably path by it) So the dragon comes down, I'm desperatly trying to get my mechanic to reset the trap, but no... he's got to be dragging whatnot to who knows where, and drinking and other less important task. Well the dragon pauses just one square to the north west of hte active cage trap and deconstructs the waterwheels and the gear assemblies. There was a water pump there, but for some reason he didn't touch it, and he just stood there not moving anywhere else. Well at that time Urist McMechanic decides to refill the cage. I see this and order him to cancel the job and all non military dwarves to head inside. While I want to capture the dragon, i really dont want to burn my legendary mechanic. So what i do is I conscript a soaper, he's practically useless so I could do without him. this soaper is a fresh new recruit and I send him the long way around my fortress. and tell him to stand on the loaded cage trap to get the dragon's attention. His death would serve two purposes. A) potentially trap the dragon, B) Unstick the dragon from whatever has his attention and send him along his merry way to my entrance (which is much more heavily trapped, and has more loaded cage traps.
Basically Green Recruit v Dragon.
So he runs up to the trap, the dragon shoots out a wave of fire and disappears, my recruit is just standing there picking boogers out of his nose totally unscathed. I'm like "whut? did he fall into the river?" I go to my unit list, and sure enough the dragon is not only in the map, but he's still alive. Further examination reveals that he's also in the cage of the cage trap. I think I'm gonna make this guy the sherrif after a stunt like that.