DC Super Friends™ San Diego Comic Con Ft. Thomas as Superman & Diesel as Batman is a promotional video that was released on the show's official YouTube channel. The video was made to promote the San Diego Comic Con and the DC Super Friends Minis theme.
Diesel and Thomas dream of being super heroes with secret identities, and have to stop the evil crimes of Charlie and James as super villains, respectively.
- Thomas (as himself and Clark Kent/Superman)
- James (as Brainiac)
- Charlie (as The Riddler)
- Diesel (as himself and Bruce Wayne/Batman)
- The Mayor of Sodor
- Sir Topham Hatt (does not speak)
- Edward (cameo)
- Henry (cameo)
- Gordon (cameo)
- Percy (cameo)
- Paxton (cameo)
- Annie and Clarabel (cameo)
- Diesel 10 (as The Joker; portrait cameo)
- Mr. Bubbles (mentioned)
- Tidmouth Sheds
- Sir Topham Hatt's Office
- Thomas' Branch Line
- Elsbridge Viaduct
- Mr. Bubbles' Puzzle Emporium
- Sodor Jail
- Mark Moraghan as the narrator
- Joseph May as Thomas
- Rob Rackstraw as James and the Mayor of Sodor
- Jules de Jongh as Emily
- Kerry Shale as Diesel
- Steven Kynman as Charlie and Ryan
- Part of this video is made in the style of a comic book.
- Ryan appears, despite not having a Minis model of him at the time.
- Steven Kynman takes over the role of Charlie from Ben Small in the US dub and Ryan from Eddie Redmayne for both dubs.
- James' face after Thomas captured him resembles his cross face from the model series.
- The original Thomas theme can be heard at the beginning and the end of the video.
- The quote "What kind of machine has ears?" was used in the Batman 1966 TV show (said by The Riddler) and is said by Charlie.
- The narrator is self aware in this story, as at the end he starts talking in his "superhero story" narrator voice before coughing and correcting himself to his normal voice.
- Annie and Clarabel's names are not written on their sides.
- When Thomas crashes into Sir Topham Hatt's office and defeats James, his number and Superman logo are missing.
- None of the engines' wheels move when they're supposed to.
- At the unveiling of Diesel's statue, some engines are on rails while some are not.