Dorfs. I know this is a D&D poll, but at this point I've associated them with dwarf fortress. Some of the stories I read about what people do in that game...
There's the normal stuff like making traps which flood a chamber with magma, so you don't have to go to the hassle of disposing of corpses... just retrieve the metal weapons and armor.
And then there's the bizarre, like draining the ocean to start a walrus breeding program.
And then there's the sick... like the autobutchery which drops livestock hundreds of feet to cut down on the micromanagement required to mark them for butchery
... or trying to capture mermaids to start a breeding program to harvest their valuable bones for making crafts.
Real dwarfs of genius, we salute you!