|First Appearance|| Rickety's Ridiculous Ruckus (Cameo)
A Diesel Railway (First Full Appearance)
|Basis||Bulleid Diesel No. 11001|
|Livery||Light grey with dark grey wheels and roof and a red bufferbeam|
|Voice Actor|| TidmouthStation25
Dennis first lived on an old, run-down railway with his brother Norman as well as their friends Bear, Paxton, Sidney, and Rusty. They were bought by Sir Topham Hatt and brought to Sodor. Norman and Dennis quickly allied themselves with the "evil diesels" of Sodor, including Diesel, Arry, and Bert in order to not have to be at the bottom of the pecking order of the "diesel pecking order".
Dennis was recently involved in Norman's attempted "Fireworks Incident". Because he is extremely lazy, Dennis has also recently tricked Thomas into doing his work for him. He also has been known to trick Percy, Stanley, and Whiff for this same reason. Nowadays, Dennis mostly hangs around with the other evil diesels of Sodor at the Sodor Dieselworks, not really doing anything except planning and scheming.
Dennis is an extremely lazy diesel who will do anything to get out of work. He often attempts to take advantage of others. Dennis will always make up excuses to get out of work. However, he usually gets caught in his trickery, and is always very sorry- that is, until he finds another opportunity to get out of work again. He often schemes and plots ways to advance himself and his friends, to the detriment of the steam engines.