When Thunder and his brother Lightning came to Jump City for the first time, they were simply having mischevious fun. Lightning, peer pressuring his brother, got Thunder to terrorize the city. When the Teen Titans attacked them, Beast Boy showed Thunder the error of his ways. Thunder then got Lightning to stop attacking the city and the two were declared honorary Titans to be called upon whenever they are needed.
Batons: When he is in the clouds making thunder, Thunder uses a set of batons that he uses like drum sticks. He hits the clouds with these sticks and thunder is created. [1]
Transportation
Cloud: Thunder, like his brother, rides on lightning clouds.