The scrap diesel of the Duckeychev Scrapyards, Diesel 10 is known to be a big bully. With a massive hydraulic claw on his roof, his main job around the scrapyard and railway is to pick up scrap and load it up, but he also handles heavy goods and demolition work. He may come off as intimidating, but will often bring about his own downfall in a goofy manner!
Diesel 10 is based on a BR Class 42 diesel-hydraulic with an added non-regulation hydraulic claw. All but two members of the class were named after Royal Navy warships, so they, and the similar Class 43, were nicknamed "Warships". Two of these engines are preserved.
Diesel 10 is painted ochre with tan stripes along his sides. His buffers and "Pinchy" are painted dark brown.
- Diesel 10 has had four models used in Crotoonia.
- The first one was used in very old Crotoonia music videos and shorts and it made its last appearance as a brief cameo in Casey Jr's Mail Run. It had black cab windows, a brown claw, and a more yellowish color. It also used Diesel 10's face from the CGI series.
- The second one was never used in the series and was only used in promotional material. This model of Diesel 10 had white cab windows, a black claw, and a more brownish color and overall updated to more accurately resemble Diesel 10 from the TV series. This also used the Diesel 10 face from the CGI series.
- The third model is similar to the second model, with the most notable difference being that Diesel 10 now has an animated face instead of using the CGI face.
- The fourth and current model has more detail and now a 3D face similar to his model appearance.