The Diesel is a made-up Friturtoons character. It was not confused with D261 (known as The Diesel) from Thomas & Friends. Like the Thomas & Friends Characters, he has a gray face.
The Diesel was sent to Friturtoon Town to help Barney, Mario & The Other Friturtoons with the mountain line, and starts to boast about being the most important Friturtoon in the whole world. But he gets himself, BJ and Bowser into disaster, and falls off the cliff and busts into flames, splashing water everywhere! He is soon recovered and scrapped.
The Diesel is rude and aggorant, and stuck-up.
The Diesel is based on a BR Class 45 1Co-Co1
The Diesel is painted in a British Rail "Rail Blue" livery with yellow warning panels.