I was on year 7 of this fortress and was starting to feel a bit unstoppable (though I feel very silly now). My Military seemed to destroy goblin invasions with ease, and my main problem became dealing with dwarves falling in the river / going over the falls (Tried restrictions, tried deleting items in river with df hack etc but they just seemed to really want to go in there )
Anyways, a Forgotten beast shows up, and it's got webs. So I know I wont be able to likely melee this thing, but it's in a very confined area, so I try anyways. Since it's made of glass I assume bolts / arrows probably not going to be so great. I send in my champion who manages to tear a chunk out of it's arm, then dies getting his head smashed in in the process. The FB picks up my champions steel boot and starts using this as a weapon and manages to crush the heads in of every dwarf I throw at him with it. I exhaust my military, though he's extremely wounded at this time I figure a few lucky dwarves might just take him out? And then I can rebuild with the small population left over (about 40 at this point as the FB has been killing miners and web collectors as well)
So I make two new squads, assigning dwarves to go pick up countless steel armor sets I had planned to sell to a caravan to build up my reputation when all of a sudden a goblin invasion of 80+ shows up at the same time!
My military didn't even get a chance to equip themselves and the last fight log I read was a militia captain getting eaten by a dog. Noone survived, though some visitors seemed to be trying to hole up in a church.
The goblins overwhelmed the FB and brought it down, though suffering some casualties, I like to think without my dwarves it probably would have murdered them all... Oh well! FUN!
Also if anyone's interested I happened to be recording this as an attempt at a let's play I had a lot of fun though I am in no way any level of expert at this titles.
https://youtu.be/8Sia76vT9S0