|First Appearance||Thomas Helps Out (Cameo)|
|Livery||Red with a cream cab and a black roof|
|Voice Actor|| Ois894WR
When Jack first arrived on Sodor, he was shocked as to how big it was, having previously worked on small railways. He quickly was sent to work with the Pack as a trial at the Boulder Quarry. When he arrived on the scene, Max and Monty quickly became annoyed by his enthusiasm. They tricked him into crashing into Thumper, sending Boulder rolling down the hill. However, after thinking quickly, Jack was able to stop Boulder from causing too much havoc, and was rewarded by being allowed to become a full-on member of the Pack.
Jack currently works with the Pack at the Blue Mountain Quarry, as well as at the reconstruction site of Ulfstead Castle.
Jack is cheerful, friendly, enthusiastic, and helpful. He is always ready to "jump in" and help out whenever it is needed. However, he can sometimes be a little impulsive. Jack is also a very optimistic engine, and what he lacks in strength and size, he makes up for in heart. He is also one of the de facto leaders of the Pack, along with Kelly and Nelson.