Yep, elves can be surprisingly hardy at times, though most of the time, they are sissies.
I remember in adventure mode when i attacked a elf retreat with a dwarf, aiming to wipe out every elf there. (which i did)
However, a elf swordsman i encountered there took an incredible amount of damage, without dieing for some time. The extent of his injuries were something like this:
My first attack was hacking his lower body,which made him vomit, then i hacked off his right upper leg, badly cut his left leg, and badly sprained his right hip. He then passed out. Next i wrestled and broke all his other limbs.
At this point i left him on the ground, while i went to kill the other elves, as i was sure he would bleed to death. Yet after 10 mins of elf killing he was still lying there, passing in and out of consciousness.
I never got to actually kill the unfortunate swordsman, however, as an elf bowman shot me in the head, poking out my eye and throat, and i bled to death.
I made a new adventurer, and revisited the retreat to kill the last few stragglers. Among them was the swordsmand i had so grievously wounded, still passing in and out of consciousness. I decided to finish him this time, but just would not die! I hacked off his hand, badly cut his spleen, and mangled/broke most of his remaining limbs. He was eventually killed when i hacked his head off.
Yeah, i'd say he was a pretty hardcore elf.
*edit i have the entire log if anyone interested.