Vegetable oil?

Where do you get this?

Any veggie kind of monster. Mushrooms would be a good start.

I think any kind of Mushrooms. Maybe Golems too. At the moment, since the invasion is insane, try Hidden Streets, maybe some Ellinia trees.

I get mine from Shrooms at HHG1 after I kill a bunch of aliens, they start spawning again.

Confirming (Dark)Nependeaths in Orbis dropping these, too.

The Dark Nependeath map is untouched by aliens, and there is a hidden street at.. erm.. Cloud Park III(?) with mixed spawn of both versions.

If you can, go to mushroom castle. If you can't, hit up the hidden streets related to mushmom/mush castle. They're untouched by aliens.

If you're in Ludi, then bizarrely enough, the Gray aliens drop it. plenty of uninfested hidden streets in Omega to gather on.

Amoria isn't affected by this, so you could hunt both oil + animal gas from there.

First map on the way to Mushmom is good.

The EASIEST thing to do if you want the animal gas and vegetable oils is to go to Utahs pig farm for the gasses, and then go one map back next to that demon doorway where a hidden street is with only blue mushrooms so... NO ALIENS! yay

There's also the slimes in the tree that grew III (a hidden street in I think "The Forest South of Ellinia") on the way to Ellinia from Henesys. Basically any map that isn't on the world/region map, or is a mini-dungeon will not have Aliens spawning in it.

Not to mention the mushroom shrine. Plenty of mushies jumping about at the first map after town.

sleepywood is very efficient if you bother to carry return to town scrolls for henesys and sleepywood. 1 map left has evil eyes for gas and ant tunnel 1 has horny mushrooms for oil. unmolested by aliens.

stone gollens drop them pretty fast, just go to golem temple in henesys

The EASIEST thing to do if you want the animal gas and vegetable oils is to go to Utahs pig farm for the gasses, and then go one map back next to that demon doorway where a hidden street is with only blue mushrooms so... NO ALIENS! yay

I'd pick this one, and add an even better place for the gasses.

Pig minidungeon.