|Occupation: Quarry Diesel|
|First Appearance: Tramway Engines|
|Portrayer: Teresa Gallagher (UK/US)|
Mavis is a feisty young diesel engine who works at the quarry. She is full of her own ideas and doesn't take kindly to advice! She has a lot to learn about trucks, but with Toby's help she is learning to be a Really Useful Engine.