In the twelfth season, Mavis was having a wash at the Sodor Slate Quarry, when she was derailed by Thomas, who was racing with Diesel.
When Spencer got on the verge of discovering Hiro, Mavis distracted him from Thomas and Percy, by guiding him to back up right underneath the operating slate hopper so he had to be taken for repairs at the Steamworks. In the thirteenth season, Mavis was awoken early by Thomas, comforted Percy who was upset about having no job, was given flowers as a surprise from Emily, who thought she was upset and attended Hiro's welcome party. She was later convinced by Thomas to shunt trucks at Brendam Docks to impress a Railway Inspector alongside Percy.
Mavis broke down one day and was taken to the Dieselworks by Salty, where she was surprised to see Percy there. In the fifteenth season, she told Spencer, who could not see properly due to heavy fog, that he was at the quarry when he thought he found the Duke and Duchess of Boxford's Summer House. She later broke down again and this time Diesel helped her. In the sixteenth season, she told Gordon to get his bufferbeam mended, even when he tried to convince her he was fine without it and helped a composer with his song alongside Thomas and some of the Steam Team.
In the eighteenth season, Diesel took her to see the sights of Sodor, while Thomas did her job at Ffarquhar Quarry.
In the nineteenth season, she got damaged by stones from the hopper and had to go to the Dieselworks to be repaired and Den was sent to the quarry to replace her. She comforted Dart when he started to miss Den and once she was fixed, she went back to the quarry.
Mavis was arrogant until being brought down to earth after her embarrassing incident at the Ffarquhar crossing. Despite this, Mavis is a reliable, honest, hard-working engine, and unusually for a diesel, shows respect for the steam engines. However, unlike most engines, hauling trucks makes her feel important.
From the sixth season onwards, Mavis has matured and acts as a motherly figure to the other engines. Still being a young engine, she still retains some of her naivety.
Mavis is a based on the BR Class 04 0-6-0 Diesel locomotive. She is more specifically based on the BR Class 04's working at the Wisbech and Upwell Tramway, as they were fitted with additional cowcatchers and sideplates so they could run near public roads.
Mavis is painted black with hazard stripes on her front and rear. She has her name and "The Ffarquhar Quarry Co. Ltd." written in white on her cab and sideplates respectively.
- Teresa Gallagher (UK; Hero of the Rails onwards - US; seventeenth season onwards)
- Jules de Jongh (US; Hero of the Rails - Blue Mountain Mystery)
- Mavis was named after the Reverend W. Awdry's neighbour in Rodborough, Stroud.
- The Australian Engine uses an identical horn sound to Mavis.
- Mavis was the last character Wilbert Awdry created before he retired from writing the Railway Series.
- Mavis has had three different horn sounds during the series run. Her current horn is the same as Diesel's from the fourteenth and fifteenth seasons.
- Mavis has gone through a couple of modifications in the television series:
- Season 18:
- She gained a lamp in the same design as Charlie's on her right (viewers' left) lampiron at the request of Sam Wilkinson.
- Season 19:
- The lamp moved to the lamp iron above her face.
- She gained a tail lamp.
- Season 18:
- Mavis' television series model is currently on display in Japan.
- ERTL (discontinued)
- Wooden Railway
- Take Along (discontinued)
- Motor Road and Rail (discontinued)
- My First Thomas
- Limited Edition Collection
- Wind-up Trains
- My Thomas Story Library (discontinued)
- Thomas Engine Collection Series (discontinued)
- Mini Die Cast Collection (discontinued)
- Thomas Town (discontinued)
- Capsule Collection
- Collectible Railway
- Nakayoshi (discontinued)
- Wind-up (normal and clear)
- Pocket Fantasy (discontinued)
- Trading Cards (discontinued)
- Mega Bloks (discontinued)
- Micro Rubber Engines
- MV Sports (in three pack with Thomas and Toby; discontinued)
|Other Sudrian railways|
|Bill and Ben • "Coffee Pots" • Mavis|
|Stephen • Millie|
|North Western Railway|
|Thomas • Edward • Henry • Gordon • James • Percy • Toby • Duck • Donald and Douglas • Oliver • Daisy|
|Bill and Ben • Harvey • Emily • Arthur • Murdoch • Neville • Rosie • Whiff • Stanley • Hank • Flora • Victor • Charlie • Bash and Dash • Ferdinand • Scruff • Belle • Porter • Timothy • Marion • Glynn • Ryan • Skiff • Diesel • Mavis • Diesel 10 • 'Arry and Bert • Salty • Den • Dart • Sidney • Paxton • Norman • Philip • Flynn • Winston • Stafford •|