From the Super Mario Wiki
Goombob is a rich young Galoomba who appeared in the game Mario Party Advance. He lives in Goombob Manor, a mansion located in the Town Area of Shroom City. One of the game's missions involves locating a seashell for him to give to his crush, Goombetty. Upon collecting the shell and giving it to him, Goombetty shows up at the Manor, and Goombob gives her the shell and asks her on a date. Goombetty accepts, and Goombob gives the player the Gaddget Dessert Menu. Goombob is also one of the three suspects when the Koopa Bank is robbed. He explained that he was so terrified, he stayed where he was. He then remembers that he heard the safe open. The ending of the game states that Goombob is considering moving to the beach with Goombetty.
Goombob's design is based on the Galoombas from Super Mario World instead of the more common variety of Goombas found in most other games. Goombetty is also in this design; however, these are the only two Goombas in Mario Party Advance who have this style.