Goomba (Super Paper Mario character)
From the Super Mario Wiki
An unnamed Goomba appears during the second interlude of Super Paper Mario, after the events of Chapter 2-4, along with his apparent partner, Gary. The two come across Luigi in Castle Bleck, having been scattered along with the rest of the attendees of the wedding of Princess Peach and Bowser. They convince him to help them find an escape route, while promising to abandon him should they fail. After a short journey, they run into a dead end and are cornered by Nastasia and a group of brainwashed enemies. Gary is brainwashed, to the other Goomba's horror. The Goomba then betrays Luigi and willingly joins Count Bleck, the only known member of the Koopa Troop to do so. After swearing his loyalty to the count, he helps the other enemies hold down Luigi, allowing Nastasia to brainwash him into Mr. L. The Goomba is not mentioned for the remainder of the game, but it is possible that he is one of the few Goombas found in the castle during Chapter 8.