It was introduced in the episode "Left in the Dark". The show presents one of the best episodes of all time, in which the Spectre Hunter is sent to the scariest place of any home: the basement. Lincoln tries to watch the episode, but first, he must beat each of his sisters to get the couch first, but when he sets the old television up for Lucy, the power goes out. After the power turns back, Lincoln beats again his sisters and gets the couch, but the episode ends immediately as he turns on the TV, much to his despair.
ARGGH! also appears in the episode "Cover Girls", where Lincoln and Clyde were watching an episode where Spectre Hunter was about to take down a ghost in a bathroom in the next episode. At the end of the episode, Lincoln was going to watch the next episode at Clyde's, but since he's dressed up as Lily (as punishment for him and his sisters dressing up as each other in order to cover for each other), he ends up getting humiliated since Clyde invited the whole class to watch this issue of ARGGH!.
In "No Such Luck", Lincoln was watching TV, and an announcer says: "Next on ARGGH!".
In "Kick the Bucket List", Lincoln and Clyde try and binge watch it, but it's too long. So they have to fast foward it.
In Other Media
In The Loud House Instacomic "Lost Control", ARGGH! is mentioned again as the show Lincoln wants to watch, as well as the reason that sends him in search of the lost remote. In the good ending of the comic, Lincoln makes a deal with Lana, where he scratches her back in exchange for the remote control as they watch ARGGH! together. In the bad endings, the remote control is destroyed or ruined by a pet or Lisa, which presumably causes Lincoln to miss his show.