I had a crippled war dog butchered to satisfy a strange mood for bones, so it didn't catch my attention that war dogs were being struck down. It wasn't until farms were getting destroyed that I noticed the forgotten forgotten beast had gotten bold enough to crawl out of the mud and start rampaging. It managed to take out a lot more war dogs, and cripple a giant tiger I just bought to train for war, before the troops finally took it down for good.
A little too late to 'beware it's poison blood!' More than a month later, a wave of paralysis deaths struck pet cats and war dogs. I sealed off the passage with the blood with grates, but children were beginning to die as well, including a few child prodigies who'd already survived their moods and made their artifacts.
Then followed the waves of violent tantrums, and some of the working population succumbed to inconsolable rages and the beast sickness. The mayor showed briefly showed symptoms of both, but since she was jailed she's shown no health problems. Oh, and my bookkeeper went insane. You know, she lost only one of seven children, she has a cushy job and a big opulent house with a smithy dedicated to her husband -- life has treated her pretty goddamn well, so I can't feel any sympathy for her, but I expect her stupidity is going to fuel more tantrums.
So far this community has survived engagements with a loss of no more than 4 each, but I don't know if it's going to pull through this.