Porter is a brown monkey with a pale yellow face, hands, and feet. He wears a blue station porter uniform, which consists of a jacket with gold buttons and two pockets on it. He also wears a hat with a badge in the front center.
It was theorized that Porter is Champ, as neither one co-existed in the same game, but no official evidence suggests this is true. This though has been proven false as Champ and Porter's birthdays are on different dates.
However, it is possible that Porter and Champ are actually brothers, as Porter's e-Card reveals that he has a brother.
Theory ends here.
In Wild World, lazy villagers will mention Porter in some conversations with the player. They will state that they had a Train Station in their village while growing up, and the "coolest monkey worked there".
Porter has the voice of a lazy villager, and the town tune of Porter is exactly the same as Simon's.