Once, I locked my Baron and Baroness into an underground dungeon while I made a device to cripple them into unconsciousness - unconscious dwarves don't make mandates but preclude other nobles of that kind from arriving. While they were in the dungeon, they had a stack of some cave syrup roasts and a well to make sure they didn't starve in the meantime.
All of a sudden, a giant olm came up through the well. My plumbing was connected to the underground river (this was in 40d) and despite the maze of fortifications that supposedly shielded my drinking sources from the monsters, the latter would from time to time rise up from the depths and savage a few unlucky passersby, like in the old 2d version.
Also, because I liked Fun, my olms were size 20, the same size as elephants and certain kinds of giants.
The olm proceeded to tear the two nobles limb from limb, earning itself a name, and then sat down on the pile of leftover clothes. I decided that this was the perfect opportunity to add to the kill lists of my champions, and sent in three of my warriors: a veteran archer, a swordsman who had single-handedly driven away goblin, and a recruit who happened to be in the same squad as the two of them. I planned for him to distract the olm while the others killed it.
Unfortunately, the archer arrived first, and the recruit last. The archer fired every arrow he had at the olm, lodging many in the olm's pale hide, before it reached him and tore his head off. Then, the swordsman charged in, yelling at the top of his lungs, and crashed into the giant olm. In their struggle, they ended up falling down the well into the underground river, where the swordsman drowned to death miserably (along with his masterwork steel armor, which I never recovered).
I decided to call this a lost cause, but before I could lock the door the squad's survivor, the recruit, had run into the room. Bear in mind that though he was a recruit, he had been training for months with my other champions; he had just never seen true combat before that day.
Wielding his golden sword, he too charged at the olm, which resorted to its tried and true technique of luring its attacker underwater, where it would drown him to death. As the olm and the recruit struggled with each other, the underground river clouded with red blood. The recruit's sword became embedded in the olm, and at that point I thought that it was over, because there was no way a wrestler could overcome such an experienced killer in its own environment. Suddenly, the background of the olm's tile changed to red, and the recruit swam out of the well victorious.
Later, that recruit fell in love with and married one of the baron's surviving daughters, and became one of my most decorated veterans, but alas, he was killed by crossbowmen before he could have a child.
On his grave is written the name "Olmbane".