Nightmare on Seville Street is an episode of The Chipmunks series.
Dave is meeting for dinner downtown with a client, and he drops the Chipmunks off at the cinema house. Alvin thinks he can see a horror film called Hideous Harold, Part XI, but since Dave is buying the tickets, he makes the decision, and gets tickets for the three to see a children's movie called Fuzzy Bunny. Alvin passes the theater where Hideous Harold is playing and sneaks in, despite his brothers' pleas that it is a movie that will give them nightmares and Dave did not want them to see, they go along with him. Sure enough, it is frightening, with the Chipmunks emerging from the cinema with their fur standing on end. Dave nonchalantly asks if Fuzzy Bunny found his way home, and Alvin remarks "it wasn't that scary".
That night, an electrical storm hits. While Dave remarks to himself he sure is glad he didn't see any scary movies, the brothers fear Hideous Harold will come to take them to "land of nightmares", and Simon devises a series of traps built from their toys. Dave is awakened by a loud noise, but his attention turns to a lightning bolt and a blown fuse. He puts on his rain slicker and fisherman's hat, then goes outside to the fuse box, only to remark he is out of spare fuses. He tries to go to the kitchen to check for a spare, but a gust of wind blows the door shut and he is locked outdoors. Dave raps on the door trying to wake the Chipmunks to let him in, but nothing happens. The rapping is indeed heard by the Chipmunks, who fell asleep, and think it is an intruder. Dave, meanwhile gets a ladder and attempts to climb into the window of his room, but mistakingly climbs to the Chipmunks' bedroom.
When the Chipmunks see the silhouette of him wearing a fisherman’s hat they mistake him for Hideous Harold, and they run to get Dave, who is gone! When the see the house is without power, Dave is not in bed, and the phone is dead, they chalk it up all to the doings of Hideous Harold, and think their only hope is to fight back with Simon's traps and Alvin and Theodore chasing after him with baseball bats. When they capture Hideous Harold in a snare trap, they hear the familar "ALVVVVIN!!", only to realize they caught Dave! In their bedroom, Dave demands an explanation for all this. Alvin admits to not seeing Fuzzy Bunny as Dave paid for them to see, and was scared by the horror film, culminating in all this. While Dave accepts Alvin's confession, he also holds Theodore and Simon accountable as Alvin suggested theatre-hopping, and they went along with it, making them also guilty of disobeying him. Dave says he will give them something to ensure they never forget not to disobey him in the future.
The following day, the storm has passed and it is a beautiful sunny day. However, the Chipmunks are indoors as they realize what they "got" from Dave is a punishment: "Housework all day?!". Theodore is glad he is over his fears of Hideous Harold, but Alvin boasts he was never scared at all. When he accidentally turns on the TV, Hideous Harold appears, and Alvin hides behind the couch in fear. Simon and Theodore laugh at Alvin's actions, for all he saw was a TV commercial for Hideous Harold, Part XII.
- The title of the episode and the horror movie Hideous Harold are based on the movie A Nightmare on Elm Street.
- Goof: When Alvin clenched his right hand while saying "We'll have to make Hideous Harold tell us where Dave is," he has five fingers instead of the usual four.
- Part of the Alvin and the Chipmunks: Nightmare on Seville Street VHS.
- Part of the Trick or Treason and Halloween Collection DVDs.