im-always-a-slut-for-ereri:

Concept: Mermaid au. Only Eren isn’t a weak frilly tropical mermaid, while Levi’s the big bad deep water mermaid. Eren’s a poisonous lion fish tropical mermaid and no one goes near him because basically everything single part of him is poisonous as shit. Levi can because his skin is tough enough that he won’t accidentally be poked by Eren’s spikes but if Eren really wanted to he could kill Levi.

OR. Eren’s the deep water, scar covered, glowy shark mermaid while Levi’s the pretty poisonous tropical mermaid.