In summary:
- Elephants were absolutely vicious in .23a, because size heavily correlated with combat-effectiveness instead of just thicker tissues. Getting Boatmurdered elephants back would probably need to alter the physical stats themselves and/or give some natural skill, including discipline. Or maybe the rage tag, which does increase strength, when it's enraged.
- Carp were infamous because of a bug related to physical attributes rising with skill (carp are constantly swimming) and an OP biting attack.
- Giant badgers at least are still quite deadly (the [PRONE_TO_RAGE:1] tag was what made them so), but what gave it that reputation was how common it was. A lot of the new animals from .34 tend to crowd them out.
- Giant sponges were invulnerable in .34 because accumulated damage and pulping had not been yet implemented, and because it had only one body and no blood, it couldn't be killed. You can add a version of the [BODY:BASIC_1PARTBODY] with [PREVENTS_PARENT_COLLAPSE], which would make it immune to the one bodypart collapsing.
I would also say, the
new demons are often more deadly than the old ones. Not just because of greater numbers, but because of the possibility of horrors like deadly dust spewing metal demons, which may be even worse than Spirits of Fire. It's perfectly possible to mod in a Spirit of Fire though. (try giving them dragonfire for !!Fun!!)
I also would
not try to spike up the giant mosquito population on the map to hundreds, since that's a good way to utterly annihilate the framerate.