Update:
The combat went around as well as you'd think at first. The marksdwarf captain punches bruised fat, and the toad punches bruised and stopped her heart, but being DF, that's no big deal. Then the toad had the terrible idea to wrestle with her, and snapped her right ankle tendon, causing her to fall unconscious, but not before she managed to get in a lucky nose scratch that turned the organ red.
Knocking my captain unconscious was a tactical miscalculation, as it meant that it focused far more attacks on her head, which had a steel helm, (rather than the bone helm I'd assigned...) instead of the leather armor on her torso, and it started doing significantly less damage.
Meanwhile, I set up a meeting zone behind the toad, and let my tamed cave crocodile out of its pasture, and it migrated out into sight range with the giant toad. It didn't actually do serious damage, but the ensuing scuffle knocked the toad into the cage traps.
I'm not entirely sure on the status of the captain. No body part is worse than yellow besides the ear and ankle, but there's a lot of blood and she's faint.
Doc Dour was well prepared for this, and is already sleeping.
EDIT:
She seems unconcerned by this, however, and as soon as my captain woke up from her pain coma, she ignored her bleeding torso, and went to go get a drink without even bothering with medical attention. (In spite of having a completely destroyed ankle and no crutch...)
Also, she now "no longer cares about anything" after just one fight. I didn't think you could get that in a single fight that literally only lasted a dozen punches before you fall unconscious.
I gave her the nickname I gave her because her husband (one of my miners), when I was looking over his personality page, struck me as the stereotypical "Red Oni" stereotype. All anger and merriment and outbursts of emotion. So, I named him that first, then tried looked at her page to see if she'd be a "Blue Oni" and...
"She is deliberately cruel to those who are unfortunate enough to be subject to her sadism. She feels a strong need to reciprocate any favor done for her. She is very quick to anger. She is generally confident of her abilities when undertaking specific ventures. She tends to hang on to grievances. She tends to be swayed by the emotions of others. She does not easily fall in love and is rarely swayed to positive emotions. She tends to avoid crowds. She lowers her voice when angry."
So I named her "Black Oni" because she was basically the most antisocial and sadistic dwarf I'd ever seen.
She also came with ranger skills, so I made her a marksdwarf. I presume she chose that job for the capacity to torture animals.
EDIT 2:
After waking up from being asleep, Doc Dour went on break. I gave up and assigned my mayor to treat the wounded after a dwarf finally chased the captain down and dragged her to bed. (Presumably against a blistering verbal abuse for pulling her away from attempting kicking puppies with her bloody mangled foot.)