3 Forgotten Beasts arrived at once.
The first one, Mothram, a friggin' gecko made of fire, turned the lone speardwarf Bim Kirbim into Bim Kirbim Irolvucaroggez Keshan (Bim Mergedsling the North Urn-Holes of Fire) upon death after basically boiling him alive. The second, Ayiti Iredesesi Fafiresofipu, a quadruped made of ice with a deadly spittle, took a while to be taken down and destroyed several buldings. As for the third, Asno Kutsmobbosa, an alligator with a shell and noxious gas, he stayed a while in the local water source, only getting out to fight a bit. Each one of them claimed a soldier (the first being Bim Kirbim). A single spearwarf was infected by the case, but so far, she's only been numb and doesn't show any other symptom after 2 weeks or so, which leads me to think she will be okay. It is probably a foolish thought.
It was pretty epic all in all, especially considering that most of the floor where the fight took place is covered in 2/7 water and the gecko was therefore engulfed
Oh, and during the attack, there was a bunch of ambushes, but they murdered each other on the border of the map instead of pillaging the fort, so...
I guess it went this way.
"Dude, I can't attack that fort. Maybe there are my natural parents in there."
"Urist, Windslap was only founded 10 years ago. You're probably 25."
"That's what you're saying! How can I know you're not lying?"
"Look, man up and shoot a goddamn midget, or your bones will help me summon..."
"Ngoxang, don't you talk like that to Urist! I raised him like he was my own little brother!"
"Oh, c'mon! Nobody asked you to do that! Beside, I always told you to friggin' kidnap them before the age of ten for a reason! Else they remember their old fortress and they go all angsty teenager on us. Remember Shorast?"
"What should I have done instead, you smartass?"
"This! *stab*"
"Oh my god, you stabbed Urist, you bastard!"
*more stabbin' action*
Several Urists away...
"What the shit are they doing?"
"I think their dwarf recruit is rebelling. Dammit."
"I always knew this would happen. Sorry, Uzno, but we can't take the risk of letting any possible traitor in our ranks."
"... but I'm a human!"
"... but he's our best recruit!"
"Shut up! I'm your leader! And I decide we..."
"*stabs* I never liked him anyway. Dibs on his socks."
"Like hell, woman, they're made of dyed rope reed fiber."
"Over my dead body!"
... and so forth.