There's one major event that recently happened in my fort...
I created a goblin ambush-alarm in the outskirt of my map, a dog trapped in a building. I'd rather use cats to bait gobbos, to control the population, but all my cats already adopted dwarves and I don't want to risk my fort to crumble due to tantrum spirals. I must emphasize, I'D REALLY RATHER USE CATS THAN DOGS AS BAIT! Anyho, to enter the room with the trapped dog the unsuspecting gobbos have to cross a small passage full of stone-traps with 3 z-level deep pits at the sides, which the stone traps should shove them into. I have never tried this approach of trap and I haven't bothered to look into similar approaches online, so I was very excited about seeing it in action!
The bait dog gave birth to some puppies while being chained inside the building. One of the puppies ran outside the building, and that's when it was spotted - a werehorse! Ferociously the werehorse attacked the puppy and killed it instantly. It went into my building and straight through the stone traps but none were triggered as these nasty creatures doesn't trigger traps. The werehorse killed the other puppies and the bait dog. Right after the bait dog suffocated the werehorse transformed into Vucar Ushatil, a dwarf peasant. He didn't seem to be bothered about the situation at all, and headed towards the exit. He had to go through the passage, as that's the only way out. BAAM! He is hit by the stone-trap and is propelled by the force straight down into the pit!
That's how I captured a werehorse.
Edit: I tried to trap Vulcar, while in human form, in a cage. I built a tunnel full of cages leading to the bottom of the pit, and when my miner struck the last piece of rock he spotted Vulcar in human form and killed him... Stupid dwarf...