From the Super Mario Wiki
Porter is a Toad that is found during the events in Paper Mario: The Thousand-Year Door. He is the porter of the Excess Express, hence his name and checks the Train Tickets of passengers before letting them onboard. Porter loves trains so much, he is said to have billions of model trains in his home.
- "That's Porter, the station manager here in Rogueport. He checks the train tickets. I hear he loves trains so much he has like, a billion model trains at home. Maybe he's just using his adulthood to buy all the things he wanted as a kid..."
- Perhaps intentionally, in the Nintendo GameCube game Animal Crossing, there is a porter monkey at the train station, whose name is also Porter. The Porter in Thousand-Year Door may be a reference to the Porter in Animal Crossing.