Dennis is a lazy diesel shunter. He has a twin called Norman and often proves to be Really Useful.
Dennis is based on a diesel shunter 11011, another member of this class is Norman.
- Season 14: S.C.Ruffey's Sweet Tooth and Flat Stanley (does not speak)
- Season 15: The Maron Station Makeover
- Season 16: Henry's Hill
- Season 17: Dustin the Really Useless Engine (cameo)