A bronze colossus turned up. The fortress is on the other side of a three way canyon with a hefty fall into a river below. We built a bridge over it. It's partially walled off, the middle open, the intent being that when it's finally filled with traps, the Goblins will begin hurling themselves over the edge. I've always imagined colossi as giant slow moving titans without much in the way of dexterity. Turns out I'm wrong. For some bizarre reason this colossus took a look at the bridge and decided that walking over it wasn't good enough. It jumped from the eastern canyon edge, grabbed one pillar at the end of the wall, swung on to the middle of the bridge, before grabbing the pillar/wall on the west, and swinging over to the west bank. This colossus is like spiderman but 80 feet tall and bronze.
A fisherwoman wandering around at the top of the mountain charges at it. They have a fight at the cliff edge. The Fisherwoman dodges the colossus' blows, and swings back. It goes as well as you'd imagine: She does absolutely no damage. But she does manage to get the colossus to dodge backwards. The fisherwoman charges at it, it dodges, she flies past the colossus and over the edge, the colossus teeters and topples. She goes down into the canyon, knocked unconscious in the impact of the water. Drowns. The colossus manages to grab the edge of the cliff and hauls itself back up.
It chases the local wildlife, kills some animals, finds a crafter. She is locked out. She attacks the colossus. They have a long fight, but without weaponry and armour, it's only a matter of time before the inevitable. Eventually it hits her in the torso, mangles her. She flies through the air rolls along the ground. Then she gets back up. They go at it again. She dodges a lot of the attacks, but with her substantial injuries she's far slower. It hits her a second time. She flies through the air and slams into a tree and crumples to the ground. More catastrophic damage to the everything. She gets back up. They have a third round before it finally breaks enough of her bones to make her faint. A random crafter woman went three rounds bare knuckle with a bronze colossus. It crushes her.
A couple of days later a trio of dwarven bards comes over the hill. They don't do as well as the craftswoman.
Currently it's just strolling around the mountainside. We're banking on the possibility that it can be sniped from atop the fortified rooftop of the pub before it gets the idea to climb the walls.