Snake Oiler does not appear in the original manga version of Speed Racer. Snake Oiler was created specifically for the television anime/cartoon series. In the original manga, Captain Terror had the personality traits that would later be given to the Snake Oiler character in the anime.
"The Car Acrobatic Team is one of the original set of characters appearing in both the manga and anime. The 16 racers' uniforms are embroidered with a letter from the English alphabet. All of the cars in the team (automobiles numbered 11 through 26), except for number 11, look and act the same. The cars sprout wings from both sides, making them capable of jumping large gaps and gorges. The most notable of the team are Captain Terror and Snake Oiler (the latter being a character exclusive to the anime).
Captain Terror, the leader of the Car Acrobatic Team, is shown as an arrogant driver in the manga, sabotaging races for his own benefit. His arrogance gets the best of him, and he gets severely injured in an explosion after not heeding Speed's warning about his car leaking oil. He has a "Z" embroidered on his racing uniform, and has a face of skeletal features and a lone feather atop his helmet. He drives the number 11 car, the only car different in appearance to the rest of the Car Acrobatic team."