Final answer:
George Carlin, a comedian known for his profane stand-up routines, served as the host of the kids show Thomas & Friends, playing the role of Mr. Conductor.
Step-by-step explanation:
The foul-mouthed comedian who hosted the kids show Thomas & Friends was George Carlin. He was known for his stand-up routines that often contained profanity and dark comedy, surprising many that he took on the role of Mr. Conductor for the children's television series. Despite that, Carlin brought warmth and charm to the beloved character, providing narration and storytelling that contrasted sharply with his more adult-oriented comedy work. It's an example of a performer's range and ability to appeal to vastly different audiences.