I embarked on the Dwarf Heaven site posted elsewhere in this forum, and had been chugging along, dealing with wildlife and rigging up my fortress and the like. About a year and a half in, a dwarven caravan arrives, landing down at the southern tail of the chasm. And then going around the chasm. Where the GCS lives. That got exciting real quick, especially when the trogs popped out behind them.
So, the battle raged, and I was just watching it go, not wanting to interfere with the natural course of things, until one heroic merchant swordsdwarf managed to take out one of the spider's eyes and damage a leg. I figured it was as good a time as any to bring the beast down, especially with all the trade good from the caravan littering its lair, so I sent my entire squad of 8 champion wrestlers (no real metal industry running yet), who surrounded the beast and fought it for days, to little effect. It got hurt a few more times, but nothing serious. In the meantime, it had killed 5 of my wrestlers. During the battle, my Mayor/Broker/Miner wandered up there looking for a corpse, adn the spider got him, too.
So, desperate to slow the tide of deaths and keep the fort from tantrum spiral, I hastily drafted my Manager/Bookkeeper/Miner, who had carved out basically the entire fortress alongside the Mayor (the two of them were best friends). He charged over the mountain in a perfectly straight line, jumped over one of the wresters who was paralyzed by venom, and chopped at the GCS, armed only with a copper pick.
The first blow, he mangled one of its legs, and the pick got stuck inside.
The second blow, he killed it. Unarmed.
So now he gets a giant golden tomb.