Molly is a yellow tender engine that was brought to Sodor for goods work.
Molly came to Sodor to handle goods work, but was very shy about it. She soon became one of The Fat Controller's more reliable goods engines, often hauling trucks from the steelworks or the coaling plant regularly. Recently, she has enjoyed the company of the narrow gauge engines and has a certain fondness for Duke's stories at The Mine Junction.
Molly was one of the engines sent to help Toby, Duck and Donald with ballast work at the mine junction. There, Duke was providing a thrilling lecture about how to handle trucks and recklessness, which was soon interruped by Bertram. The scene becoming much too hectic for shy young Molly to handle, she left the yard and returned to work.
During a trip to the docks, Molly encountered Rheneas who was guarding a line of trucks that he claimed to have been "jinxed" by the new engine Young Tucker, which he claimed would not move after Young Tucker had shunted them into place for Norman to take, causing the latter to overheat and break down. Molly, not believing him, went over to talk to Young Tucker, who truly believed that he was jinxed. Molly didn't believe him, and so took the train in place of Norman, but found that they moved easily, but was unaware along with her crew that the air brakes had been damaged when Young Tucker had shunted them, and that they were no longer hard-on, but now off and completely useless, allowing the trucks to push Molly into the sea. However, Young Tucker quickly came with Rocky to fish her out, and the two officially became friends.
Molly was sent alongside Charlie to Sodor Tramways on repair detail. Molly is intent on getting to work, however Charlie is more concerned with getting Molly to lighten up, employing increasingly quirky comedic schemes in attempts to get her to laugh. Charlie's overbearing attempts cause Molly great discomfort, causing her to become quite agitated and rash. After one such encounter, Molly was taking a train of supplies up to the repair point when icy rails cause her to careen into the frozen river and quite ironically "break the ice". Following this incident, Charlie comes clean and apologizes to Molly, and she forgives him, admitting that she sometimes gets a little too tied up in her work. Lightening up, Charlie's final act of self-depreciating humor is finally the necessary catalyst to get Molly to laugh.
Molly is meek, shy, and not fully confident in herself. She is always worrying about the other engines' opinion of her and is very self-deprecating. She is a very clever and talented engine all the same, but she is the only engine who will not acknowledge her own worth. Molly is still very kind, and does her best to boost her own confidence for the sake of herself.
She also has the tendency to be very focused on her work, treating any distractions which make her uncomfortable with increasing impenitence.
Molly can be known to give advice she does not necessarily agree with, but only because she is compassionate and wants her friends to be happy, safe, and sound.
- Season 1: Lift Bridge (cameo), Swagger and Swerves (cameo), Splatter (cameo), The Old Warrior, Shepherd's Pie (cameo), Conspiracy Theory (cameo)
- Season 2: Grim Messengers of Doom (cameo), Scot-free (cameo), Mavis and the Tornado (cameo), Rosie (cameo), Young Tucker, Rock-Star, Pummeling Percy (cameo), Tag-Team, Blunderbuss (cameo), Swashbuckler (cameo), Thomas and the Fortune Teller (cameo)
- Season 3: Logan Leaves his Mark (cameo), Samson, BoCo, and the Man in the Hills (cameo), Derek and the Two Faced Engines, Penn Pals, Ice Breaker
- Web Clips: Mike and Frank Banter: SLOTLT, ScarletFire, and EE93's Return (cameo), Gina gives Percy some pointers - Meet the Characters! (cameo)