Bud Grouse is a recurring character from the Nickelodeon animated series The Loud House. He is an elderly, widowed, curmudgeonly man who lives next door to the eponymous Loud family. As his surname would suggest, he is often annoyed by the constant antics of the Louds, and sometimes appears to heckle them.
The show's first Christmas episode, "11 Louds a Leapin'", marks the first time in the series Mr. Grouse would have a prominent role in the plot. In that episode, it is revealed that he is always taking away the Loud kids' things if they end up in his yard. When this happens to Lincoln Loud's sled, "Big Red", Lincoln attempts to sneak in and retrieve it, only to end up breaking it when Mr. Grouse catches him in the act. In the process, however, Lincoln learns that the reason Mr. Grouse doesn't enjoy Christmas is because he lives very far away from his own family and is unable to visit them. After Lincoln tells his sisters about this, they, along with their parents and the McBride family, present Mr. Grouse with a special Christmas present - a bus card so that he can go see his family tomorrow. Touched at their kindness, Mr. Grouse invites them in to spend Christmas Eve with him, giving back the Loud kids' confiscated items and also apologizing to Lincoln about his sled getting broken. The next morning, Lincoln finds that Mr. Grouse, dressed as Santa Claus, gave him his old sled that he owned as a kid.
Three seasons later, Mr. Grouse has a very brief cameo in "Season's Cheatings", the first segment of the show's second Christmas episode. At one point, Lincoln, frustrated that his plan to get a Rip Hardcore backpack for Christmas isn't working out, opens his bedroom window and screams. This startles Mr. Grouse as he's putting up his Christmas decorations and causes him to fall off his ladder.
In the second Christmas episode's other segment, "A Flipmas Carol", Mr. Grouse has slightly more screentime. At the beginning of the episode, on Christmas Eve, Flip charges him $500 for an entire bin of Christmas lights. Mr. Grouse is later seen having put the lights up around his house, but they fail to work when he tries to turn them on. In the process, he falls off his ladder again and all the power in his house goes out. The next morning, Flip, having had a change of heart thanks to being visited by some ghosts, shows up at Mr. Grouse's house to fix the lights.