"Trolley" is a semi-anthropomorphic character that made it's first appearance in the long running show Mister Rogers' Neighborhood.
The Neighborhood Trolley is the trolley that passes by the fictional Neighborhood Of Make Believe to deliver messages to the residents of King Friday's castle. The trolley did not talk. To communicate, it makes a 'Ding Ding' noise, and often moves back and forth. It often passes through the Neighborhood, carrying unseen passengers of the Neighborhood.
Trolley was housed in a tunnel by the window seat - the Trolley bench. Trolley appeared when Mister Rogers turned on the switch. Mister Rogers made a point to show children that he was the one controlling Trolley, and that he could make it go forward or backward, slow or fast.