- "Why, that is the cutest little whistle!"
- — Katherine commenting about Theodore's whistle
Katherine is a red cargo ship from Serbia who, like Emily said that she had never met a ship from Russia until Gregor was in the harbour, she also once said that Theodore's whistle was cute.
Appearances
- Season 2 - Theodore's Whistle, The Tugboat Pledge (cameo), Snorri the Viking Ship (cameo) and Emily the Vigorous.
- Season 3 - Grumpy Garbage Barge (not named)
Trivia
- In the books, Katherine's hull is painted yellow.
- Katherine's model was later used for Inverness and S.S. Malarkey, and her structure was later used for Stewiacke.