He was formerly The Chosen One foretold in legend who would stop The Darkness but his destiny was given to Timmy Turner after he accidentally slept through The Darkness' attack. He has the ability to shoot lightning bolts from his armpits.
Turbo Thunder is about a few inches shorter than Jorgen Von Strangle's base height. He also bears a strong resemblance to Timmy as they have the same hair color (although Turbo Thunder's is much longer and slightly darker), eye color, similar front teeth and pink color on their outfits. He has the same body shape as his father and his hairstyle is similar to that of his mother.
Turbo Thunder lived with his parents happily on their home planet, Wonder World until The Darkness attacked. It swallowed up everything and everyone there except for him.
Turbo Thunder ended up on a planet which he named Thunder World, where he trained to combat the Darkness, and to build a home for himself. He eventually fell asleep and missed the Darkness' return, failing to complete his destiny.
When he was sent to the Blue Moon of Vegon, he made a pet rock, Rocky to be his companion so he wouldn't be lonely.
The fate of Turbo Thunder finding himself on an empty planet with stone friends is similar to how Bizarro Superman ended up.