Lengthy Attack on Titan dream in which I got killed by fucking titans like eight fucking times. I got an exciting plot twist after all that, though: some casual dialog between Armin and Mikasa reveals that people in Titanland don't know where babies come from. They just kind of show up, at the base of the Pale Towers.
The Pale Towers themselves are structures that appear occasionally near human settlements, always just at the border of a forest. They are always either windowless and made of thick slabs of sandstone, carved with strange blurred images, or unfinished-looking frameworks of fresh-cut birchwood. They are always eventually destroyed by titans.
Each year some young unmarried people are rounded up and brought to the towers by singing flying saucers made of sandstone, where they have to... have sex, I guess? This is implied, I guess, because Mikasa thinks whatever it is is upsetting and kind of boring, and Eren is terrified of it. But Armin came away bleeding and with a broken arm the time he did it, so maybe not? Or maybe he's just like, particularly bad at it? I don't know, my subconscious thinks it's Andrew Hussie, it was all coy about this.
The point is that sometimes titans come and destroy the towers and eat the people in them while this is taking place, and that's considered normal. People go along with this because the titans will show up en masse and destroy your city if the kids don't go to the tower and do whatever.
No one seems to be drawing a connection between this shit and the babies showing up because everyone is really stupid. What's going on, Mikasa figures out when she infiltrates an evil lab somewhere or other, is this: the titans are how humans reproduce. They somehow psychically feed on (or physically participate in?) the activity taking place at the towers, and occasionally literally feed on the people doing it, and use whatever genetic stuff they gathered up there to make babies, which they leave for the humans to raise because they don't know what these are. (Or maybe they eat some of them, I don't know, the dream didn't go into this.)
So the titans are Mother Grubs and/or Ooloi. Way to go, brain, you totally figured that one out.
Another section of the dream had velociraptors surrounding my high school, which was fine, and T-rexes which had mastered wizardry, which struck me as deeply unfair. They're already T-rexes, they do not need to be wizards as well.