There once was a titan who lived in confusion. His memories were hazy until one day most of it came back to him. While he still doesn't know the whole story, he still has a goal in his mind: don't let his friends get hurt. Titan!Marco AU. Spoilers for the manga.

Marco wakes up in the forest of giant trees, not knowing how he got there. After making the grim discovery that he has been reincarnated into a titan, he wanders aimlessly until he finds Jean, about to meet his fate with a titan ready to devour him. Will they recognise each other and restore the bond they once had? Titan!Marco x Jean AU

AU In a world where winged beasts control the skies, humanity has taken to hiding underground. Petra Ral, a young, naive soldier, finds herself trapped in a dragon's den on what should have been a routine mission. Expecting death, she instead finds that not all monsters are the same. Levi/Petra

It's not like Jean expected to see a face he recognized so soon after his death, much less in a rather different form... (Titan!Marco. Rated for safety)

Slight AU! there's a story circulating in the Scouting Legion about a strange titan that lives outside the walls and has been deemed the 'gentle titan.' While out on a mission, Jean Kirschstein experiences this strange titan firsthand. But it seems so oddly familiar...