Well, in my personal-non-succession game, I've had a bit of an "incident"
The Dragon, name here has arrived!
Ohhhhhhhhhhh Shiiiiii-
Well, the Dragon proceeded to just hang out on the eastern edge of the map for a long time, so I decided that it was bugged, or stuck, and it'd basically ignore it, checking in on it every once in awhile.
"So-and-so the CarpenJack cancels Fell Tree: Interrupted by Dragon"
Ohhhhhhhhh Shiiiiiiii-
I center on him, and the thick forest above my fortress is UNRECOGNIZABLE. Ash everywhere. No trees within like a screen and a half of the entrance. I immediately tell my dwarves they have to get inside, and draft my meager army and move them to just past the traps of my base's entrance (maybe the Dragon will get caught in a cage!!). Unfortunately, the Dragon is between my dwarves (like 8 of them!) and the entrance. He kills a bunch of their cats, and one of my fisherdwarves.
He's chasing them all over the map, breathing fire in huge spurts that instantly ashifies any trees it touches. He breathes, and I watch in horror as the flame washes over my Rancher and one other Dwarf. A quick look at their wounds, and both are unconscious with like half their body red. He moves nearer and lets loose another blast of flame....
and the game crashes.
I'm actually happy that it crashed almost, as I'm pretty sure that was going to spell the end of my fortress.
Except that I have it set to autosave seasonally, and when I load up the file, the Dragon is sitting there on the edge of the map. I've left all my dwarves inside for now, and the Dragon has sat over there for the entire season of spring (potentially he was why the Elves never made it to my fort). I can't wait to see where this goes tonight.