Thunder real name Gan Willaims, is one of the many honorary Titans from the show Teen Titans and comics. As his name implies, he controls thunder and can shoot blue thunder beams.
Thunder first appeared in the episode Forces of Nature, where he and his brother, Lightning, have fun but intentionally cause havok in Jump City. The Teen Titans face them, in whic Beast Boy convinces Thunder that causing wreaking the city is not funny and it is wrong. When the two brothers flee the Titans, Thunder starts to think that Beast Boy was right, but Lightning tells him that Beast Boy speaks nonsense. When Thunder and Lightning attack Beast Boy and Starfire, Beast Boy tells Thunder that he does not want to hurt him. Thunder in turn, tells Beast Boy that pain does not amuse him. Thunder and Lightning then follow an old man (who is actually Slade in disguise) who allows them to use their powers to cause stick targets to burn. Slade then brings to life a fire creature. Thunder and Lightning then attack the Teen Titans to prevent them from defeating the fire monster. Thunder tells Beast Boy (as a tiger) to stand aside but Beast Boy does not listen. Beast Boy then tells Thunder that gifts do not need to make him special, it is how he does it. Thunder realizes his mistake and attacks Lightning, telling him that their fun must stop. Just as Lightning was prepared to finish off Thunder, Thunder tells him if he is still having fun, to which Lightning tells him he does not and cancels his attack. Thunder and Lightning then use their power to create rain in which they use to defeat the fire monster. The two brothers then apologize and are rewarded with a communicator in case they need help. Thunder is later seen again in the episode Calling All Titans, in which he is attacked by I.N.S.T.I.G.A.T.OR. and Steamroller. The two villains capture him and he is frozen by the Brotherhood of Evil. Thunder is later defrosted in the episode Titans Together and helps the other Titans defeat the Brotherhood of Evil and their allies. Thunder is last seen at the end of the episode helping the Titans recapture Dr. Light.