He doesn't appear, but has appeared a lot of appearances in the comics.
Prior to the Teen Titans
Five years before Starfire's arrival on Earth in the episode Go!, the Gordanians invaded the planet Tamaran. The lush planet was soon ravaged and war-torn. As the threat of a takeover by the Gordanians became even greater, Wildfire was secretly sent away to an unknown part of space in order to preserve the royal family line of Tamaran, and has not been heard from since.
The Return of Wildfire?
The two spend the day in Titans Tower, and Starfire introduces her younger brother to all the Titans present and her pet, Silkie. Silkie has a negative reaction towards the young Tamaranean, which surprises Starfire, who apologizes for the actions of the moth larva. Wildfire replies that he does not like animals much, gaining a suspicious look from Beast Boy in the background, and Starfire begins to speak about the pet that Wildfire had when he was a child, before trailing off and stating that she is "merely disappointed that Wildfire and Silkie did not get along instantly." Starfire then proceeds to introduce her younger brother to two 'delicacies' of Earth—pizza and mustard—while Robin contacts Galfore expressing concern about Wildfire's actions. Galfore attempts to reassure the Titans leader, while Starfire gives Wildfire a tour of the Titans Tower.
Later that night, the two siblings are exhausted after a long day of touring and storytelling. They both head off to bed. Soon after, Raven and Cyborg are attacked by none other than Wildfire—who the Titans discover is actually Madame Rouge in disguise. A battle ensues, but Madame Rouge manages to escape. A crestfallen Starfire mourns the fact that her brother has not truly returned, but states that there were "too many things wrong about him." However, she also realizes that there were also things 'right' about him. She deduces that Madame Rouge could not have worked alone, and figures out that it must have been their evil older sister, Blackfire, who had helped the shape-shifter. Starfire flies to the prison where Blackfire is currently being held and informs the older Tamaranean that her plans have failed. Furious that Blackfire would stoop that low just to destroy her, Starfire renounces Blackfire as her older sister, and swears to find her long-lost younger brother because "He is the only family she has left!"
- In the original comics, Ryand'r meant "Darkfire".
- In the original comics, he is with a group of alien superheroes called the Omega Men. In theory, he has been with them all this time fighting against the Citadel and other forces of evil across the Milky Way galaxy.
- It could be that Blackfire has indeed seen Wildfire, knows of his whereabouts; since Madame Rouge had disguised herself according to Blackfire's description of her brother.