Timothy is a reanimated criminal mastermind bent on the destruction of the 08S.
Timothy's past is unknown. At somepoint between Season 2 and Season 3 he was seen on Sodor by Percy.
Timothy was the main antagonist and stayed in the shadows until the final battle. His gang attacked various locations and people on Sodor and eventually captured incredidite, a nearly indestructible metal. They also killed Thomas the Tank Engine. Off-screen, Andy brought Thomas' body and the incredidite to Timothy on the Mainland. Timothy lured 089 to him by contacting him via com system and sending his assistant Gerard to go find him. When 089 arrived, the incredidite fused with Thomas' body and Timothy posessed it. A fight broke out. Timothy posessed various objects in the yard and managed to defeat 089, but the latter eventually prevailed and knocked a tired Timothy through his shed and off of a cliff. 089 was knocked off of the same cliff by Gerard moments later. The next day, 089 and Timothy woke up aboard Johnny Cuba.
Timothy will return along with 089 in A Tale of Two Trains.
Not much is known about Timothy or the way he acted in the past. After his rebirth in The Road to Sodor, he has acted like a child throwing a tantrum. He claims to have come back to kill all of the 08S, screams wildly, and attacks his enemies by possessing other things in the environment. What goes on in his head has to be the stuff of nightmares...
- Timothy posessed other engine corpses aside from Thomas. The engine corpses in Timothy's Abode were previous engines he tried to posess.
- Timothy is based off of Timothy the Ghost Engine from the infamous Thomas and Friends Creepypasta: The Untold Story of Timothy. However, the Quest 89 version is more of a parody of him. He isn't a demon, he's just insane, according to Nick.