i think it's fun how there's a whole class of bugs in dwarf fortress's history that are just, "everything it working as it should, but these features are interacting in ways we did not expect"
like giant sea sponges being nigh unkillable in combat because of their lack of bones and organs. or cats dying of alcohol poisoning in taverns from getting booze all over them and licking it off. or the (unpatched and probably never to be patched) Minecart Shotgun
the cat thing was fixed by having tavernkeeps also clean up spills instead of just passing out drinks, and the sponge thing was fixed by adding that just. generic flesh or bodily tissue can be damaged
also yes giant sea sponges can become hostile and attack, and get up on land. prior to the fix the only reliable ways to kill them were magma or atom-smashing (a bridge coming down on anything just erases it from existence)
as for the minecart shotgun:
if you get a minecart going at high speed and suddenly stop it, its contents will fly out, maintaining their velocity.
so what you do is, you get a very lightweight minecart filled with heavy objects (lead or gold things work best for this). you then get it going at a very, very high speed, and slam it into a fortification, on the other side of which is a long, wide tunnel enemies are coming down. the cargo goes through the fortification while the minecart does not, and due to their speed and weight, the objects act almost like cannonballs, ripping chunks off and holes through any unfortunate creature they hit.
you can also have an automated cart return system where the cart falls and is caught on another rail, which sends it back to be reloaded.
also, don't let your dwarves you value go on a ride in the shotgun. it will force them through too small a hole (the fortification) and thus mangle them beyond recognition.
