Bud Grouse is a recurring character from the Nickelodeon animated series The Loud House. He is an elderly, 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 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 unsuccessfully attempts to retrieve it, and in the process, 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.