Molly, nicknamed "Claud Hamilton, Jr.", is a yellow tender engine, who use to work for the London and North Eastern Railway. She is seen quite frequently pulling passengers and goods around the railway. Molly has four large driving wheels.
BioMolly was sensitive when she arrived to the railway, Emily teased her for hauling empty trucks, Molly disappointed of her job. Thomas tried to make her feel important by decorating the trucks and telling the engines Molly had an important job. However, this backfired when the wind blew the tarpaulin covers off, and the engines saw the empty trucks. Molly was embarrassed and decided to runaway, but she learnt the importance of her job when the engines at the coal depot needed her empty trucks for their trains.
Once, Emily had to work with Whiff, to collect rubbish trucks. Molly was one of a number of engines who laughed at her, along with Neville and Murdoch. Emily decided to runaway from Whiff but she soon learnt to work with him. Now, Emily doesn't care of what the other engines like Molly think of her, when working with a smelly engine.
One icy winter, snow drifts blocked the line and the engines had to wait until it was cleared. However, James had an accident with pipes, so Molly was sent to bring Rocky the crane to help remove the pipes. Molly was surprised to see Henry, who was searching for his lucky trucks. Henry had to wait for the line to be cleared before he could start his journey, and soon Rocky helped clear the his pathway.
She has shown to have good knowledge about sail boats. When Thomas was carrying the Mayor of Sodor's sailing boat, he didn't wait for the sail to be tied down properly. As he went under some trees the sail unraveled and the wind went up, blowing Thomas down the track. Thomas past Molly and she advised him to slow down, but Thomas was going so fast he didn't here her. Thomas realized his mistake and secure the mast again.
Molly helped prepare the railway for Sodor Day. She was well aware of Thomas' disappearance and went looking for him. Molly received news from Bill and Ben that Stanley had found Thomas. She and along with all the other engines, attended the festivities at Great Waterton and Thomas realizes just how important his friends are.
Molly is proud of her strength, but is very sensitive. She wants the other engines to think the best of her. Her feelings can be easily hurt and embarrassed, but she does have the courage to do things right. Molly can usually be-found pulling coaches or stunting trucks around Sodor.
Molly is proud of her strength, but Molly is also very sensitive. She wants the other engines to think the best of her. She finds any conflict very upsetting and steams away to avoid it.
Behind the ScenesMolly's scale model for the television series was Gauge One. It was able to blow smoke from its funnel and had over 5 faces, which were removable. She was Radio Controlled and was given moving eyes. Originally Molly had a larger face, this can be found many promotional shots of her. This is assumed to be a prototype face, as it was never used in the television series. Molly's model is currently at display in Canada at Nitrogen Studios.
BasisMolly is a Great Eastern Railway D56 Claud Hamilton. Claud Hamiltons were built at Stratford Works from 1904 to 1911 and named after the chairman of the company. Two of this class were appointed to Haul the Royal trains to Sandringham.
Molly is painted bright yellow with gray and red lining and white-trimmed wheels.
- Molly's whistle sound is really Thomas' in a lower pitch.
- One of the models Molly is currently displayed was by Nitrogen Studios.