Culdee is a purple mountain engine who appeared in The Railway Series.
- Culdee has buffers, a feature he does not have in book illustrations.
- Culdee is one of three engines produced that only appeared in the Railway Series. The other two are the Big City Engine and D199.
- The Culdee inside the prototype box has a lighter shade of purple.
- Culdee's image on his prototype box is a picture of his take-n-play model rather than a CGI-styled image of him.