Susan Finden named her cat Casper because he kept disappearing, visiting doctor’s offices, office buildings, and pharmacies near her Weymouth home. When she moved to Plymouth in 2006 she was too busy to monitor his daily activities, and so three years later she was surprised to learn that he was riding buses. The drivers, who looked out for him, told her that he would journey 11 miles to the city center and back, sitting on a favored seat. They would let him out opposite his house.

“I couldn’t believe it at first, but it explains a lot,” she said. “He loves people and we have a bus stop right outside our house so that must be how he got started — just following everyone on.”

Ironically, or perhaps inevitably, he was finally killed by a taxi. The news of his death brought condolences from around the world, and Finden wrote a best-selling book. “He will be greatly missed,” she wrote in a note posted on Casper’s usual bus stop. “He was a much-loved pet who had so much character. Thank you to all those who befriended him.”