Red X

"Not everybody likes to play the big villain, kid. I'm a thief. I'm not threatening your precious city, just looking out for number one."

- Red X

Red X is an anti hero in the Teen Titans series.

Appearance
Red X's appearance is that of a person dressed in a completely black bodysuit that has a red-x placed right over his left pectoral muscle, an ash-gray utility belt with matching gloves that have red Xs on the palms and back of the hands, a pair of black boots with steel-soles and a black cape that has an ash-gray interior.

His mask consists of a white skull, which has no lower jaw, on a black full-face mask and a red x starting on his forehead and with a point of the x is ending beneath his right eye. The eyes are white reflective lens, which seem to act like Robin's mask as making facial changes to his actions, and are outlined in black.

The new wearer of this outfit is shown to be of similar built yet a couple inches taller than Robin

Personality
"Robin: I thought you didn't like playing the hero! Red X: Doesn't mean I don't know how."

- Red X and Robin

Red X's personality is the one major difference between him and Robin. While Robin was Red X, he was even more serious than normal and kept his goal of capturing Slade as his top priority. The new X, however, is a thief who is "just looking out for number one", stealing purely for monetary gain. This Red X is revealed to be far less serious, finding his battle with the Titans amusing and voicing derogatory quips as he immobilizes them with his gadgets. He even flirts with Starfire, indicating that he and Robin both share similar tastes when it comes to girls though it might also be an example of his flippant sense of humor.

On the other hand, despite being a self-serving robber, he is not without heroic qualities. He rarely preforms acts of true evil and, when the time comes for him to use his powers to prevent disaster, he tends to rise to the occasion. In his initial appearance, in the episode "X", he ends up helping Robin against Professor Chang and freeing the rest of the Titans. Later, in "Revved Up", he enters the race for Robin's personal secret, but, after Robin saves his life, he repays the favor by taking out the other villains participating in the race and disappears right afterwards. He has since become one of the most popular characters to have appeared on the series.

Origin
Red X started out as an evil Alter-Ego of Robin so he could get close to Slade and what he was planning, but in a later season, someone stole the Red X suit and decided to wear it and become a thief.

Red X (Robin)
When the Teen Titans first encountered an army of Slade's Robots, Robin want to figure out who he was, and what he was planning. So he created an Evil Alter-Ego to figure out Slade, but in the process, Robin almost crossed the line between Good and Evil, and almost lost his friends.

2nd Red X
After Robin quit being the Red X, the suit was never seen for some time. Until someone stole the suit and decided to wear the suit and become a thief. He only stole stuff so he could look out for what he considers as Numero Uno. But when Raven, Cyborg, Starfire, and Beast Boy were kidnapped by Prof. Chang, Red X decided to help Robin take out Chang. But he only did this to steal the Xenothium to power up his suit. However Robin anticipated this so he managed to take Red X's belt. X manage to steal one tube of the Xenothium and used it to create a distraction and manage to escape from the Titans.

Red X made another appearance, and became a member of Brain's Brotherhood of Evil. When Ding Dong Daddy manage to steal something precious from Robin. Because it was valuable to Robin, all the Teen Titan villains teamed up and tried to steal it from DDD, while preventing the Teen Titans from getting the Briefcase, including Red X. However near the end of the episode, Red X saw in Robin's eyes that it was really valuable to him and decided to take out the other villains that wanted the briefcase. What happened to Red X is unknown. During the fight between the Teen Titans and the Brotherhood of Evil, Red X wasn't spotted, it's likely that he left the Brotherhood after the Ding Dong Daddy race.

Powers and Abilities
Physically, Red X is an accomplished acrobat and martial arts fighter on par with Robin. In fact, their combat techniques are quite similar, giving weight to the common suspicion that both once had the same tutor (which would be Batman).

Red X's powers derive from his suit's belt. The belt relies on power from a (possibly artificial) element called Xenothium. The suit is also fitted with an invisibility or cloaking device, and a teleportation device. The palms of his gloves can also form x-shaped manifestations which can act as shuriken, wrist-mounted blades, restraints (by constriction or adhesion), timed explosives, instant openings, or any other conceivable function. Robin noted that he created Red X's main weapon systems as specific ways to beat each of his fellow Titans.

In the episode X at the end Robin reveals that he took his belt. Red X smashes the xenothioum in his hand and jumps into the clouds. At his next appearance he somehow had stolen it back, as he is shown using his suit's powers again.

Trivia

 * It's been hinted that Red X really is Jason Todd, Robin's adopted brother from the Batman comic book series, as his name appears on Beast Boy's whiteboard "theory" of Red X's true identity.
 * There is other evidence in the show for Red X being Jason Todd– specifically his explosives skill, acrobatics skill, knowledge of the Robin and the Titans, as well as his self-serving and violent tendencies.
 * Red X may also be an alternate name for Jason Todd's Red Hood, similar to Deathstroke using the name Slade, possibly to downplay the connection to his comic book counterpart for the purpose of mystery or suspense.
 * In the Teen Titans Go! comic, it was briefly shown that Red X had a daughter known as Pink X. It was later revealed that this was really Killer Moth's daughter Kitten in disguise.