Haunted/Sinister/Terrifying

[doom king]

I have been wondering, what are the differences between all of the different evil surroundings?

[kheftel]

https://dwarffortresswiki.org/index.php/Surroundings

[Levan Shprota]

Savagery (as in, the amount of big scary fauna and its hostility).

Sinister is Calm Evil, Haunted is Regular Evil, and Terrifying is Savage Evil.

[Jyggalag]

The most fun biomes.
The kind of place where it's the food that wants to eat you.