Goompa

Goompa is Goombario's grandfather. He is an elder Goomba, and has extensive knowledge about the world. In fact, Goompa taught his grandson everything he knows. His knowledge of the world comes from his adventures as a youth. In his prime, he used to travel the globe with his friends Koopa Koot and Bootler. Goompa also has a bad back.

Goompa lives in Goomba Village with the rest of Goombario's family. In the beginning of Paper Mario, Goompa is fixing the veranda of their home with a Hammer. When Mario attempts to leave the village, Kammy Koopa appears. Using her magic, she creates a yellow block that prevents Mario from leaving. Mario decides to ask Goompa for his Hammer, and walks to the veranda. Unfortunately, the veranda has fallen apart, causing Goompa and Mario to plummet to the ground below. In order to get back to the village, Goompa will temporarily join Mario. Although he doesn't fight, he teaches Mario how to use the game's battle system and gives Mario his Hammer after it is found.

Later, at the end of Chapter 1, Goompa had the Tape Koopa Koot loaned to him a long time ago and wanted back. If Mario asks for the tape to Goompa, he will get from the back of his chair and give it to Mario.

Trivia

 * Goompa's name is a portmanteau of "grandpa" and "Goomba", a namesake which he strangely refers to directly. As a matter of fact, "Goompa" may be a general term for Goomba grandfathers, as Goombario occasionally refers to Goompa as "my [his] Goompa".
 * It is implied that he was the Goomba martial artist who trained The Master.
 * Goompa constantly has his back turned while fixing the veranda, and making him turn around (by talking to him) reveals that he does not even have a Hammer while doing so. Nintendo most likely left these details out to avoid having him hold a Hammer, as he (like all Goombas) lacks arms. Later games would be less shy about having Goombas hold objects; Mario Superstar Baseball, for instance, depicts the one playable Goomba's baseball bat as simply "floating" in the air. The "floating" thing may explain how he fixed the veranda.  Otherwise he may have held the hammer in his mouth.  This will never be known.
 * It is clear that he dislikes Shy Guys from the tape that Koopa Koot lent him that depicted suffering Shy Guys.