Not exactly a very epic dwarf... but sweet nonetheless.
I nominate a maggot. In my military, trainees start out as pump operators and stone-smoothers (lets face it, one legendary engraver who does not haul objects is much faster than a herd of idiots). I call them maggots.
This girl was the last trainee accepted in my maggot military program.
With less time, she became "Unbelieveably Agile" and "Unbelieveably Tough" and "Very strong", while all the other morons were either tough, strong, agile, or none of the above.
Within time, I accepted another, just so she could have a sparring partner. It took another two years before the last of the idiots assigned to the maggot program even got close to her level. I handed them both iron shields, swords, and full chainmail armor, and let them spar.
Not five minutes after the other was accepted, my legendary miner(I believe he was as strong, tough, and agile as you can get), entered a fey mood. I couldn't get him the supplies he wanted, and he went on a murderous rampage... that didn't last long. I stationed the girl outside of the mason's workshop, for several seasons. Had her carry food, and sleep on the ground. She never got unhappy. As soon as the miner went berserk, she walked up and sliced off his head. She never got harmed. I renamed her from "Conscript" to "Hero". (At first, I let the miner go. He killed ten people. I re-loaded, and stationed her outside. She saved ten dwarven lives. She deserves the title of "hero").
Another season later, my fort was seiged. I stationed her outside my still-unfinished series of cage traps, and she held off an entire seige by herself. She was swarmed by goblins of all types, and killed enough to break the seige. Sadly, she was killed in the process, and the other moron went to have a drink while she was left defending the entire fortress... alone.
A later seige, I captured 19 goblins and a human. In cages. I decided to build an arena. I have a platinum statue and coffin, containing her bones, in the center of the arena. Now, anytime a "conscript" wants to become a "soldier", they must kill a fully-armored goblin. Or two. Or three.