Flat-Top is the brick truck from the musical Starlight Express. Often played as a punk, Flat-Top tries his hardest to be seen as the rebel without a cause. Still, underneath it all, he's actually a sweet and caring kind of guy. He idolizes Greaseball but doesn't see how mean Greaseball is until he later beats up Rusty. Even though Rusty is his friend, he almost always follows Greaseball and his gang, tagging along at the back. Otherwise he hangs out with Dustin the Big Hopper.
He has also been played as a prepubescent boy, anxious for status and desperate to be one of the gang even if it means initiation hazing, whilst still the kid of the freight yard trying to prove his worth there too(though he generally opens his mouth just in time to put his foot in it.). He has split loyalties, between his Freight friends and wanting to be cool with the Diesel gang. With CB removed from the show in late London, he was probably the deepest and most complex character on stage. While he apparently condones Greaseball's gang beating up Rusty(without actually throwing a punch himself), he sneaks back after they've gone to give him back his racing helmet and check that he's alright.
Flat-Top has no solos and hardly sings. The only time he is really heard is during Freight, the original rap, and Poppa's Blues. He is a fascinating background character however, as he struggles to resolve his allegiances to the Freight(his 'family') and Greaseball's Gang(who are cool and wear sunglasses even when it's not sunny, and let him tag along with them sometimes).
Since Flat-Top is the brick truck, his costume is basic grey, covered in graffiti. His flat-bed shoulders are piled high with bricks. There are chains on his arms and waist. In London he had a foam brick on a chain(attached to his wrist) velcroed to his belt, which the actor would then improvise with(the brick has been a yo-yo, a mobile phone, a nail file, a pet, a mouth organ, a comb, a sandwich, a talking parrot, and occasionally a brick.). The Broadway design moved the brick to the top of his head, and took away the chain, so he can no longer play 'fetch' with it or lob it at the audience, safe in the knowledge that it will return.
His original London Costume seems to indicate he hails from the Great Western Railway while all other costumes don't seem to point this out.
On Starlight on Ice, Flat-Top becomes more colorful than before and a bit more scary. He seems to have scars on his face along with some stitches. His outfit is now yellow, green, blue, red and orange. He is defined as the Flatcar and wears a strange looking head piece.