Donald and Douglas were two Bio-Fused Scottish twin engines. Douglas was voiced by Pauls Vids.
Nothing is known about Donald and Douglas' past before they were Bio-Fused.
The doctors and specialists at HiT Logistics locked Donald at the pressure chamber, causing Douglas to wonder where he is. While Douglas is wondering where Donald is, his face and the sides of his boiler fell off, revealing a fleshy mass underneath his body, which slowly began to expand; because of that, the glass door quickly shuts. After the glass door was shut, Douglas immediately exploded, causing blood to splat over the glass window.
- There was no true explanation of what really happened to Donald while he was locked in the pressure chamber. It is possible that Donald has died of suffocation in the pressure chamber due to the telepathic link with Douglas, or somehow survived in vice versa.
- There was originally going to be a scene where one of the twins chase the employees in HiT Logistics. However this was never shown in the final cut. This was presumably cut out because it would contradict the film's logic that one twin's death means the other. By including it, they would create a plothole over Annie's death (the entire reason for the third act) in that Clarabelle's death killed her but not Donald's?
- The deleted scene where one of the twins chase the scientists in HiT Logistics makes people assume with the theory that Donald had busted out of the pressure chamber after the death of the other twin (which turned out to be Douglas). This could possibly mean that Donald may be alive.
- According to Paul on Twitter, Douglas would have originally had flesh arms and his eyes would have fell off with his face when he died. However this was changed because "The arms looked rubbish and the eyes were too comedic"
- This version of Donald & Douglas didn't use tenders like most Thomas & Friends related videos do, as Paul confirmed on Twitter that neither twin would be getting tenders because they wouldn't be visible in any of the twin's appearances.
- However the twin's tenders were seen in both Shed 17 & Project G-1 via stock footage from a few Thomas and Friends episodes.
Shed 17 Universe
- Thomas The Tank Engine: Shed 17 (Donald only; stock footage cameo)
- Thomas The Tank Engine: Project G-1 (Donald does not speak)
- Roly's Christmas Special (Donald or Douglas)