Theo (he also goes by his racing name "Turbo") is the main character of Dreamworks Animation's Turbo franchise. He is an oridinary snail who dreams of becoming the world's fastest racer (a goal continually shot down by his brother Chet). Spunky, up-beat and eternally enthusiastic, Theo gains insipiration from his racing idol Guy Gagne. Through a series of extraordinary circumstances, Theo gets superpowers that allow him to race very fast. It's because of this power that he joins Whiplash and hiscrew of gardensnails.
In the theatrical film, Ryan Reynolds voices Turbo. Ryan just uses his natural voice here, but to be frank, it works. It's the casual, happy-go-lucky, smooth performance that is Ryan Reynolds.
Dominic Catrambone takes over for the Super Stunt Squad video game. Dominic sounds closer to Ryan than Reid does, but it's a little too deep for my liking. A good voice, just not a perfect Ryan Reynolds-match.
In the flash-animated F.A.S.T. series, Reid Scott voices him. Reid seems to be doing his own thing here, rather than trying to emulate Ryan. It's higher and even more peppy than Ryan's voice.