Oliver is a Great Western tank engine who works on Duck's Branch Line.
Oliver and Toad were escaping from scrap when Douglas found, saved, and brought them to the North Western Railway. The other engines were impressed by his adventures and the attention soon went to Oliver's smokebox. He was so conceited that he ignored Duck and Donald's advice about trucks and several pushed him into the turntable well. Upon his return from the Works, Oliver regained his respect after pulling the ringleader of the trucks, S. C. Ruffey, apart. Oliver has since had many adventures, such as running Thomas' Branch Line during the engines' trip to England, discovering an abandoned house which was later turned into a tea-house, spending a night as a snowman after crashing into one in the village, and being saved by Emily when he was about to be hit by Thomas. He then gave Gordon instructions when he was lost. Later, he was constantly telling Toad the story of how they escaped from scrap, and was then very surprised when Toad told Oliver about his own adventure.
- Oliver is also best friends with Chief Thunderhooves.
- Oliver along with Toad, guest star in Brian Griffin's Adventures of Transformers: Age of Extinction and Brian Griffin vs. The Mummy: Tomb of the Dragon Emperor.
- Oliver is also Annie's boyfriend.
- Oliver is Lyra Heartstrings boyfriend in Mustang Fan's series