Bill and Ben were two Bio-Fused tank engine twins.
Information about Bill and Ben's past was never mentioned before they were Bio-Fused into BagNall 0-4-0STs "Alfred" and "Judy" tank engines, except that they were one person before Bio-Fusion.
The twins are shown being experimented on to test the telepathic power of Bio-Fused twins. At one point in the video, one of them is shown concentrating so hard that they crack a pane of glass placed in front of them. The telepathic link between Bill & Ben resulted in them having extreme phycic powers.
- There was originally going to be a scene where one of the twins shoot lasers at Vinnie Smith while Terry and a surgeon perform tests. However, this was not seen in the final cut of Project G-1.
- Despite the fact that Bill and Ben were last seen alive, Paul has confirmed on Twitter that the twins were dead: either incinerated or assimilated into Project G-1.