Everybody gets wars wolves. Sieges are a depressing time for the soldiers.
I gave the goblins / orcs war wolves, spiders and elephants. Then I felt this was a bit too much so I gave my dwarves
war-bears.
In a response to this daring move, the ice-raiders (a race composed of viking versions of superman) started to train up their
platoons of penguins.
Yeah, I like giving my civs war animals, the
stranger more culturally appropriate the better.
Most of my forts also have an entrance as elaborate as is feasible at the time, such as dragons' maws rising from a magma moat, or a giant speartrap-filled aboveground tunnel, made entirely from ice.
And death pits, the more the merrier. Current fort has a tower with 4 walkways branching off at the top, each delivering prisoners into a different pit. There is are regular, spiked, magma and drowning pits. All are inescapable.
The regular pit also has a bridge that attests the poor prisoners' fall a few levels short of them dying from the impact, retaining a few wounds instead. They can then walk along the bridge into a side room...which is a large coliseum, right next to the 'extremely dangerous' animal pens, and has a few handy access hatches in the ceiling for soldiers / condemned criminals / animals to be dropped in.
Sort of like the Roman coliseums, if the criminal / prisoner can kill whatever else is in there with him, he goes free. For the soldiers it's just a live-action training exercise. For the animals it's a free meal.
Win / Win situation for all involved!
EDIT: I think there is also a subset of humans modded to only settle in deserts, also with location-related war animals, but they don't show up much. Something to do with the whole 'vast swathes of desert are only in super-tweaked world-gens'. I need to find more...
I also thought about modding in some sort of shark-demon, sort of like the regular frog ones, but significantly more badass. And less slimy.