Completely off topic:
Sergals?
As in these sergals?
yes. check the modding forums, someone made them as a possible civ that you can use.
back on topic though, the weird thing about this is, i would gen the world once, it would come up perfect with sand, magma, hfs, an underground pool, and some large pockets of magnetite all in a 5x5 area, and i can add in chasm if i go 5x6, and terrifying biome.
i have a copy of the folder saved prior to messing around, so i erase the region, add the new entities and creature files to the raws, and then regen the world, and it comes up as a serene biome, no magma, no hfs, no pool, no magnetite.... all it has is a single circle chasm where the underground pool was.
now i tried erasing those extra entity and creature files, and it still gens as the serene area, not the original..
but the original copy of the df game (seperate copy of df for every fort i make) with that perfect location saved, i can gen it over and over and over and it comes out the same, the only difference is the towns move.
edit:
OH DEAR GOD WHAT HAVE I DONE!!
in the first season i got a caravan from the northern sergals. ok, cool. i colapsed a floor onto the depot and stole their stuff.
fall comes around... 'a caravan from the southern sergals has arived' and i think sweet! and i just finished replacing that floor...
then a few seconds later 'a caravan from the goblins has arrived' and im thinking 'the hell???'
and then a few seconds later 'a caravan from the ender goblins has arrived' and then the purge goblins sent a caravan, and then the terrifying goblins sent a caravan... so now i have 6 caravans all trying to fit in my one trade depot...
and then i get 'a vile force has arrived' as the orcs start a siege... i still only have my original 7 and no migrants!!!
edit again!
more hilarity! the 'friendly' goblin merchants decided to smash all of my buildings... and refuse to let me rebuild them