The Rogue Titan is a Titan in Shingeki No Kyojin. Unlike other Titans of the series, the Rogue Titan has no interest in attacking and devouring humans, but instead fights and kills its own kind.
The Rogue Titan is none other than Eren Yeager, one of several humans who can shift at will into Titan form.
The true name of this titan, and the accurate translation of the series' title into English, is the "Attack Titan".
This tag implicates titan_(shingeki_no_kyojin) (learn more).