Rivetra

Rivetra is the het ship between Levi Ackerman and Petra Ral from the Attack on Titan fandom.

Canon
There is the scene in episode 21 during the Female Titan Arc when Levi stops to see Petra's dead body. Even though he says nothing, you can just see the sadness in his eyes. Second, in episode 22, Levi takes Petra's badge from her jacket. If you listen closely you can hear the piano version of Call Your Name in the background. Also in episode 22, there is the scene when Petra's body is thrown off of the cart. If you are a manga reader, you know that the scene was never drawn into the manga, signaling that Hajime Isayama sat down and told the directors to add it in. Then there is the infamous "letter scene" with Levi and Petra's father.

During an interview, Levi Ackerman's Japanese voice actor, Kamiya Hiroshi says "リヴァイ的にはペトラ気になりますよね (REGARDING LEVI IT’S PETRA THAT I AM CONCERNED ABOUT.)". The voice actor absolutely adores Petra. Another quote is from Petra Ral's Japanese VA, Natsuki Aikawa. She says in a tweet “Someone told me it would be exciting (moe) if Heichou pushes Petra against the wall (kabedon). I understand! Totally understand!” (This is a rough translation). I believe that this quote pertains to when Petra tells Eren not to be scared of him, and Levi and Petra are left alone in the same room. Lastly for quotes, is what Author, Hajime Isayama, says in a Q&A.

As well both of the English voice actors have said the word about these two. During the SacAnime Winter 2015 - Attack On Titan Panel, the English voice actors for Annie Leonhart, Mikasa Ackerman, Petra Ral, Levi Ackerman, and Armin Arlert were asked who they shipped in the show. Nobody knew how to answer the question until Lauren Landa (Annie Leonhart) said, "I honestly can probably see - well not anymore, but Petra and Levi.". Matthew Mercer (Levi Ackerman) says "Yeah, I could see that too." which is responded by Caitlin Glass (Petra Ral) with "They would be like the cleaning King and Queen . Also, during the Attack on Titan panel Q&A at KrakenCon 2014, Matthew Mercer and Caitlin Glass were asked to improv a scene where Petra confesses her feelings to Levi.

On the birthday cards and Valentine's Day Events it shared some much more information. On Petra's birthday card, it was confirmed that she was the one who picks out Levi's clothes. In the Valentine's Day events, in 2014, they were chosen to be the couple for the event.

Fanon
Levi consistently dominates fan popularity polls in both Japan and the West. Because of this, it has become one of the more popular pairings of the franchise and is also widely considered to be one of the most popular het ships in the fandom. As well as Petra being one of the most popular female characters in the fandom, getting them to a rank within the top 5 ships in the Attack on Titan fandom.

Fandom
FAN FICTION

TUMBLR

PIXIV

Trivia

 * The two have tea together late at night.
 * Petra is the only one who calls Levi by his first name in Squad Levi.