I think the Sierra RR (Oakdale dinner train and owner of the track to Jamestown) had a visiting "Little Engine that Could." It was not nearly as popular as TTTE but a valiant attempt.

Thomas has TV, the Little Engine just has books. The only "Mr. Rodgers Trolley" I know of was in an amusement park, and the "Toonerville Trolley" is long lost to popular culture- though there was a Toonerville ride at the Oakland Zoo at one time. The followers of the Fiddletown and Copperopolis are mainly older railfans. Disney has its comic railroad roller coaster. I don't recall any other character/comic trains, especially ones (such as TTTE) that can be packed up and brought to a museum to attract a huge bundle of toddlers dragging their parents around.

Thank goodness for television marketing?