Hector

Hector is a coal hopper with "HECTOR" on his sides who first appeared in the eleventh season episode "Hector the Horrid" when Bill and Ben brought him to the yards to carry coal. Hector, at first, was aggressive, roaring at the engines, "Keep away!". This gives Thomas a fright and scares Rosie away. Thomas, determined to shunt him, accidentally pushed him off the line, and after being helped back onto the rails, Hector revealed he was intimidating so he wouldn't have to carry coal, being scared of doing so. Thomas showed him it was actually quite fun, and now Hector is one of the more friendly trucks.