I started in an evilish area. I am on the border of a Terrifying Biome and a Wilderness Biome. So far I haven't had constant waves on undead, but I tend to only see Giant animals or animal people, and not normal animals. Also instead of rain, it rains Dwarven Blood and only dwarven blood. All my grass is covered with dwarven blood puddles.
So I built into the side of the mountain and faced off against a couple of Goblin sieges. The second ended when I got the message, "The dead has risen". I was then treated to an absolute slaughter as goblins were completely overrun by zombies. I set a row of traps and now I have a few zombies in cages, which I have rigged outside of my fort as a first line of defense next time the goblin's show up.
So another year went by, I am experiencing a baby boom, 48 babies with a total population of 150. I then had to face my biggest threat yet, Giant Mosquitoes. I spent about a month fighting back against a giant mosquito infestation, which ended up littering the fields with mosquito chitin. Then the goblins decided to show up again, which ended the same way, another zombie invasion. This is when I saw one of the new developments. All of those random mosquito parts came to life and assaulted the goblins, once again a massacre. A few months later I managed to clean up the infestation in time for a diplomat from Forge home to arrive and to my surprise this is what I was greeted with.
I am going to inspect legends to see what happens, but I think my king may be undead.