Hello DF forums! As a long time lurker i have been thinking...
What if the undead spawned from evil fog had different properties? I thought of these changes.
Thralls: Not exactly undead anymore. Instead creatures caught by Thrall fog contract an extreme and permanent bloodlust violently engaging anything nearby (living or undead) with a large power boost (similar in strength of pre-nerfed thralls at least i think they were nerfed at one point...). Similar to berzerk, but jacked up on steroids AND adrenaline! If a thrall is slain, their twisted hatred will temporarily cling on to life undead to cause as much damage as they can before fading away and becoming innert.
Husk: Technically isn't undead, but will immediately become undead if killed. Husks now are completely passive simply drooling and slowly shambling, completely ignorant and oblivious even when attacked around much like an empty husk. They serve not as a direct threat but rather a really annoying and hard to kill nuisance (considerably harder to put down than regular zombies) getting in the way, stinking with miasma and causing bad thoughts (though they can certainly be a huge threat to the fortress if they got contagious slime or dust on them). Perhaps (but probably not) randomly give them the ability to go through doors for maximum annoyance and so they aren't easily delt with...
Zombie: Just like they are right now...
And another thing... living slime or sludge that occasionally spawns from evil rain to crawl up to and infect your dwarves!
What do you guys think?