-Eren was known for fighting with local bullies before Shiganshina fell.
-In a flashback, his father notes that he does not make friends easily.
-He has the highest Titan kill record by far of all the former graduates of the 104th Training Corps, though he has killed only one Titan in human form with his vertical equipment abilities, and the rest have been killed using his Titan abilities. In human form, the most kills belong to Mikasa.
-Hajime Isayama stated in an interview that due to the fact that he and Eren are "polar opposites", he had a hard time writing for the character until around the fourth volume of the manga.