Duke is a brown narrow gauge tender engine.
- Season 1 - Fire Escape (portrait; cameo)
- Season 2 - Sir Handel Comes Home and Peter Sam's Prickly Problem (does not speak)
- Season 3 - Pop Special (cameo), Little Old Twins (cameo)
- Season 4 - A Blast from the Past
- Season 5 - Gallant Old Engine (cameo) and Steamroller (cameo)
- Season 6 - Resource and Sagacity (cameo), Donald's Duck (music video cameo)