Percy's Birthday is a My First Thomas-style colouring book, part of the 2002 Thomas Learning Series.
It is Percy's birthday today but he is dirty so the Fat Controller sends him to have a wash down. Percy already had one last week and did not like cold water. Thomas wishes him happy birthday but Percy is cross that he has to get a wash down on his birthday. Gordon does the same. In a last attempt to avoid it, Percy pretends he is too tired but his driver says otherwise. There is a new engine wash that Percy is to go into. He keeps his eyes shut in the engine wash the water tickles him. He is finally shiny clean but now he wants to go in again. His driver doesn't let him since he is already clean. The Fat Controller then asks Percy to shut his eyes and when he opens them, a surprise party is thrown. The Fat Controller blows out his candles and Percy wishes that he could go in the engine wash again.
- In the tenth illustration, Percy is not on the rails.