- SpongeBob SquarePants
- Gary the Snail
- Shelley (cameo)
- Frankie Billy
- Norton (debut)
- Female crossing guard (debut)
- Marching Band
- Didgeridoo player
- Dolly (mentioned)
- Patrick Star
- Mirror SpongeBob (debut)
- Lenny (orange; debut)
- Officer Rob
- Ugly Barnacle (mentioned)
- Purple Leech Creature (debut)
- Squidward Tentacles
- Fred (blue)
- Scooter (purple)
- Tina Fran
- Abigail Marge
- Jimmy Gus
- Nancy Suzy Fish
- Billy's Mom (debut)
- Nat Peterson
- Margie Star (mentioned as "Mom")
- Sam Star (deniably mentioned as "Sister")
- Other Bikini Bottomites
SpongeBob wakes up one morning and realizes that it is Sunday, and so decides to have an ice cream "sundae" for breakfast. However, he sees he has no ice cream, and finds standard toppings like bananas and cherries to be blasé, so he instead creates a new type of sundae made from onions, ketchup and the contents of a nearly-dead potted peanut plant. Unbeknownst to SpongeBob, the result of eating the sundae is intense halitosis.
After breakfast, SpongeBob begins his Sunday to-do list, which consists of saying "Hi!" to everyone in town. Unfortunately, the townspeople are universally disgusted by the smell of SpongeBob's rancid breath and run away from him. SpongeBob is very confused by this, and asks Patrick if he notices anything wrong with him. Patrick, not having a nose, can't discern the foul odor. After running down a list of possibilities, Patrick comes to the conclusion that SpongeBob is simply ugly. SpongeBob is dismayed by this revelation, and isolates himself in his home.
Later, Patrick visits SpongeBob, who has resigned to become a hermit. Patrick tells SpongeBob the story of The Ugly Barnacle, which fails to cheer him up. Patrick then encourages him to take pride in his ugliness. It works, and SpongeBob's confidence grows, so they decide to go see a movie at Reef Cinema.
As they take their seats, all of the movie-goers still try to avoid SpongeBob, which angers Patrick and sends him into a tirade. Patrick forces the other viewers to look at SpongeBob. With every word SpongeBob speaks, the viewers panic and flee, soon leaving no one in the auditorium. Patrick gets hungry, so they go to the lobby to buy a snack. However, no one is at the counter. Instead, SpongeBob pulls some of his sundae out of his pocket and gives it to Patrick. After eating it, Patrick feels a sudden urge to use the bathroom.
While washing his hands, Patrick asks a fish next to him for some soap, but he quickly runs away. Upon finding no one will stay within his vicinity, Patrick fears he has caught "the ugly" from SpongeBob, and hides in a stall with a paper bag over his head. Eventually, SpongeBob smells Patrick's extremely foul breath and comes to the realization that they are not ugly, but simply have bad breath from the sundae. Immensely relieved, the two begin to run around shouting, "We stink!" melting down the theater around them with their noxious breath. SpongeBob and Patrick run into Squidward, looking at wigs in a window display. SpongeBob cries out in joy, "Guess what, Squidward? We stink!" leaving Squidward staring blankly as SpongeBob and Patrick start running away laughing and cheering.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Dangerous (c) - Mladen Franko [title card]
‣ Hawaiian Hula - Terry Day [opening]
‣ Lonely Violin - Dick Stephen Walter [Gary playing violin]
‣ Hawaiian Hula - Terry Day [peanut plants]
‣ On the Beach - Kapono Beamer [SpongeBob has bad breath after finishing the sundae]
‣ Nostalgic Hawaii - Jan Rap [SpongeBob saying hi to everyone]
‣ Shock (f) - Dave Hewson [everyone runs away]
‣ Seaweed - Steve Belfer [SpongeBob finds Patrick sitting on a bench]
‣ Harry's Back - Hans Ehrlinger ["Maybe it's the way you're dressed."]
‣ Steel Licks (d) - Jeremy Wakefield [reflection test]
‣ The Nightmare Begins (a) - John Devereaux [SpongeBob asking people if he is ugly]
‣ Hawaiian Link (b) - Richard Myhill ["I'm ugly...!"]
‣ The Last Judgement - Peter Lea-Cox [organ music]
‣ Monster Chords (c) - Peter Lea-Cox [organ music]
‣ A Day by the Sea - Dick Stephen Walter [The Ugly Barnacle]
‣ Hawaiian Cocktail - Richard Myhill [spiraling]
‣ Me for You - George Callert ["Okay, now, say it."]
‣ The Land is Ours - Gregor F. Narholz [SpongeBob saying he is ugly and proud]
‣ Hawaiian Link (a) - Richard Myhill [movie theater exterior]
‣ Legends of Hollywood (a) - Ron Goodwin ["Pardon me, ugly sponge coming through."]
‣ Hawaiian Link (b) - Richard Myhill ["I'm not always as confident as I look."]
‣ On Fire - Gregor F. Narholz ["What is wrong with you people?!"]
‣ Vibe Link (b) - Richard Myhill ["Oh wait, Patrick, I just remembered."]
‣ SpongeBob Closing Theme - Steve Belfer, Nicolas Carr [SpongeBob saved some of the sundae]
‣ Samoa Hotel - Salvatore Assenza, Franco Zauli [Inside the bathroom]
‣ Shock (c) - Dave Hewson ["I caught the ugly!"]
‣ Hawaiian Breeze - Jon Jelmer [Patrick with a bag over his head]
‣ Shock (p) - Dave Hewson ["You gave me the ugly!"]
‣ Seaweed - Steve Belfer [SpongeBob smells Patrick's breath]
‣ Vibe Link (b) - Richard Myhill ["Sundae..."]
‣ Hawaiian Link (a) - Richard Myhill ["We're not ugly, we just stink!"]
‣ Chief Taravana - Kapono Beamer [ending]
- This episode is available on the Nautical Nonsense and Sponge Buddies, Complete 2nd Season, Complete Second Season and First 100 Episodes DVDs.
- As of August 14, 2016, The Internet Movie Database (IMDB) gives this episode a rating of 8.9/10 based on 188 ratings by users. TV.com users give this episode a rating of 8.6/10 based on 176 votes.
- This is the first season 2 episode in airing order.
- SpongeBob refers to the ketchup by its true pronunciation rather than what it says on the product label ("catsup").
- A few scenes from this episode have become popular internet memes. These include:
- The scene where Patrick holds SpongeBob up and shouts "Look at it!"
- This meme is called "Patrick Wants You To Look At It," where something else replaces SpongeBob.
- The Ugly Barnacle story told by Patrick
- The shot where Fred is seen screaming. He has been commonly referred to as the "Deuueaugh fish" because of this. Several videos include him screaming this phrase for long periods of time. (Ten hours, ten minutes, etc.) There are also videos of the scream in multiple languages. Currently, the most in a single video is 27.
- This is the first episode where Patrick's eyebrows are "Z" shapes. With the exception of "Big Pink Loser," all future episodes will feature this design instead of the original sideways "M" shape.
- In the DVD commentary, it is mentioned at the end of this episode that Squidward had a deleted line. After SpongeBob and Patrick hug him and run away, he would say "Ugly and smelly, two for one," but it was cut due to the whole screen fading to black at the end.
- The giant calendar that SpongeBob is flung into by his bed at the beginning is a gag reused from "Boating School."
- Running Gag: People run away when SpongeBob talks due to his horrible breath.
- MY LEG: The marching band gets irritated with the stench of SpongeBob's breath after they bump into buildings that they got thrown into.
- This episode has a pretty high kill count:
- Norton's body layers fall apart.
- SpongeBob's reflection commits suicide by smashing himself with a hammer.
- Two fish commit suicide by reeling themselves up with a hook.
- SpongeBob causes a car to explode, killing the driver.
- The Ugly Barnacle was so ugly that everyone died. (This however is not a scene that occurs in the episode; it was an event revealed by Patrick in the story.)
- SpongeBob's bad breath causes two fish to go belly-up in the movie theater.
- Another fish gets her face destroyed by SpongeBob's breath.
- When SpongeBob and Patrick run around in joy, their rancid breath eventually melts down the entire theater.
- There is an online game based on this episode, titled Stinky Swagger.
- This and "Bossy Boots" are the first episodes not to appear in chronological episode number order. Instead of airing after "Your Shoe's Untied"/"Squid's Day Off," which would be chronologically in order of episode number, it had first aired after "Hooky"/"Mermaid Man and Barnacle Boy II."
- This is the first time that a Steel Lick plays.
- International versions of this episode's title card don't get the right background.
- At the beginning of the episode's Audio Commentary, it originally going to start out with SpongeBob who was going out to buy every gallon of ice cream in town and he didn't know the brand of ice cream he bought was onion and then he eats it and gets bad breath. But they later decided that he would make his own nasty sundae with ketchup raw onions and peanut plants with dirt.
- After SpongeBob finishes his sundae, he says to Gary, "You know what they say, Gary... I'm easy like Sunday morning," a reference to the lyrics to The Commodores' song "Easy in 1977."
- The shot with SpongeBob playing the organ and wearing a mask is a reference to The Phantom of the Opera.
- The Ugly Barnacle may be a reference to The Ugly Duckling by Hans Christian Andersen.
- When SpongeBob says, "Hello, Dolly!," he references the 1964 musical of the same name, which was later made popular by Louis Armstrong.
- At the beginning of the episode, SpongeBob puts his blanket on like a cape, which is a reference to Captain Underpants.
- Unlike previous episodes where SpongeBob is seen wearing glasses, the glasses he wears in this episode are a parody of Groucho Marx.
- After SpongeBob goes from bedroom to his kitchen to make the sundae, when he opens the door, his bedroom wallpaper is shown instead of his living room's; SpongeBob's bedroom is not located next to his kitchen.
- A brief glitch can be seen and heard during the title card sequence. This has occurred on Nicktoons and Nickelodeon airings of this episode for several years. There has yet to be an explanation for it.
- When Patrick sees SpongeBob in his house playing the organ, SpongeBob has a mask on, but after SpongeBob turns around and Patrick lifts him up, the mask is gone.
- When credited as Animation Director, Edgar Larrazábal's last name is misspelled as Larrazabla.
- At The Reef, SpongeBob and Patrick first sit in the front row. But later, when Patrick lifts SpongeBob, they appear to be in the middle row.
- When SpongeBob talks to the blue woman in the red dress, the fish in the background change colors from blue to green to red.
- When Patrick says, "Don't worry about him, SpongeBob," the fish turns back to green.
- As Patrick speaks to SpongeBob about how ugly he got, he mentions that he does not have a sister. However, he does, as seen later in "Big Sister Sam."
- However, it could be possible that he forgot about her, due to his stupidity.
- At the Reef, when SpongeBob and Patrick get into the theater, it is in a wide-shot and Fred is at the end of the front row. However, when SpongeBob and Patrick pass him, he is at least two seats in and next to Dave.
- On the VHS/DVD releases, UK airings, Ukrainian version, and YTV airings of this episode, the scene where SpongeBob says, "Hi, building," and causes the building to flee from his bad breath plays the following audio: "SpongeBob: I just don't get it! Patrick: I don't either!" instead of what it should be. According to the Season 2 DVD commentary, this was an audio error. It's made obvious since SpongeBob's mouth still clearly says the intended line. Strangely enough, the closed captioning on home media uses the correct line. In subsequent releases (e.g. the The First 100 Episodes), the captions have been updated to match the incorrect audio.
- The music also repeats itself incorrectly at that point.
- Also, the bag on Patrick's head in those versions is brown, instead of blue and yellow-striped.
- At the Reef, when SpongeBob and Patrick arrive in the theater, it is in a wide-shot and Tom is next to the red fish, Harold. However, when SpongeBob and Patrick get to Harold, he is sitting next to the red-haired fish.
- Also upon arriving, almost every seat has someone in it, but when SpongeBob gets to the front row, very few seats are filled.
- At several parts in the episode, SpongeBob does not have the smelly breath cloud.
- In the bathroom, when SpongeBob first opens the stall door, Patrick's reflection does not move.
- For a split second when SpongeBob yells "Patrick!" a majority of his holes are missing. However, the reflection on the floor has holes.