- Patchy the Pirate (original airing only)
- Potty the Parrot (original airing only)
- Squidward Tentacles
- Clam (mentioned)
- SpongeBob SquarePants
- Slimy trash can creatures (debut)
- Gary the Snail (cameo)
- Frankie Billy
- Nathiel Waters
- Jimmy Gus
- Shelly Fishbowl
- Eugene H. Krabs
- Fred (blue and vermillion)
- Nat Peterson
- Norma Rechid
- Abigail Marge
- Miss Shell
- Frank (lifeguard)
- Martha Smith
- Medley Fishbowl
- Susie Rechid
- Miss Rechid
- Don the Whale
- Frank (muscular goldfish)
- Frank (red shirt)
- Harold Bill Reginald Scott
- Jennifer Millie
- Mr. Mayor
- Squidina's mother
- Vera Fishbowl
- Green officer
- Officer John Slugfish
- Monroe Timmy
- Tina Fran
- Old Man Jenkins
- Dolphin warrior (debut)
- Francis (light brown; normal with Green lips)
- Taylor Fishbowl
The episode starts at Squidward's house, Squidward tries to make a self-portrait when he is interrupted by a song that SpongeBob is singing about how he has an "attitude of gratitude". After Squidward tells SpongeBob to stop, he slips on some spilled paintbrushes, falls down the stairs and through the floor, breaks a plumage pipe, resulting in spewing water.
When SpongeBob offers to help, Squidward denies that he needs help and tells SpongeBob not to help him ever again. He tightens the pipe so much that the water can't get through. Squidward then walks off grumpily as he's late for work.
At the Krusty Krab, Squidward rudely yells "Pardon me!" to a purple fish while entering, then walks to the counter and tells SpongeBob to stop staring at him. Squidward scolds everyone that he says he doesn't have time to count pennies when a fish tries to pay for a Krabby Patty with a huge pile of them, comments at a blue fish eating a Krabby Patty tapping his foot on the floor, gets mad with Nat Peterson for holding the door and leaving fingerprints, thinks people are leaving "trash" on the tables, insults a frail woman's clattering dentures, and a red fish's tall hat. He even scolds a blue fish for taking too long to eat and another for taking too long in the bathroom. When SpongeBob passes by still singing about his attitude of gratitude, Squidward scolds him to stop. SpongeBob asks whether he has an "attitude of gratitude," but Squidward says that he is the most miserable person (which means the rudest person) in Bikini Bottom due to the fact that he hates his job and neighbors, and doubts it can get worse. Immediately afterwards, a previously dormant volcano erupts. Everybody in the Krusty Krab evacuates because it is falling to pieces. Mr. Krabs sees no point in trying to run away and demands Squidward's and SpongeBob's life essence after the cash register is destroyed until someone points out the shelter.
In the shelter, the mayor is trying to calm everyone, but they won't stop worrying. When the mayor ultimately thinks that Bikini Bottom is doomed, a mysterious dolphin warrior comes in and says that they must sacrifice the most miserable person. When Squidward goes towards the door, SpongeBob says that they must find the most miserable person, but Squidward mocks him. They then realize Squidward is the most miserable person, so they attempt to sacrifice him. They remind Squidward of what he said and that he even admitted to being the most miserable. Before they throw him into the volcano alive, SpongeBob offers to be thrown in because he made Squidward miserable. Squidward accidentally falls off a ledge and asks SpongeBob to help him. When SpongeBob reminds him of his promise, Squidward takes it back and SpongeBob saves him. Meanwhile, the pipe at Squidward's house has built up so much water that it sends the house flying, and it falls into the volcano. The dolphin then says that he was going to say that the most miserable person's house must be sacrificed, and the people are once again calmed; except for Squidward, who now has no roof to sleep under, and is even more miserable. SpongeBob then lets Squidward sleep under his pineapple.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Hawaiian Slide - Nicolas Carr, Jeremy Wakefield [opening]
• Attitude of Gratitude - Casey Alexander, Derek Iversen, Eban Schletter
‣ Steel Sting (a) - Jeremy Wakefield [Squidward falls down the stairs]
‣ Ascending Tension Bits - Nicolas Carr, Sage Guyton, Jeremy Wakefield ["This is your fault!"/Squidward uses the wrench to tighten the pipe/Water about to escape from the pipe]
‣ Another Krusty Krab Day - Michael Bolger, Nicolas Carr [Squidward goes to work]
‣ Silly Shenanigans - Nicolas Carr, Barry Anthony [Squidward complaining]
‣ Who Said That - Nicolas Carr, Barry Anthony ["I hate my job, and I live in a dead end town with neighbors I can't stand. I'm the most miserable person in Bikini Bottom!"]
‣ Hand to Hand Combat 2 - Harry Bluestone, Emil Cadkin [volcano erupting]
‣ Steel Sting - Jeremy Wakefield ["Oh, yes, of course, ma'am."]
‣ Action Stations 1 - Harry Bluestone, Emil Cadkin [volcano shelter]
‣ Chinese Mystery - Nino Nardini ["We've got it under control."]
‣ Steel Licks - Jeremy Wakefield [parking tickets]
‣ African Conflict - Norman Dane [ancient warrior introduced]
‣ Out of the Crypt - Harry Lubin ["...because I was the only one who knew how to stop it."]
‣ Drama Link (c) - Hubert Clifford ["A sacrifice must be made of the most miserable person."]
‣ Steel Sting (b) - Jeremy Wakefield [everyone arguing]
‣ ? [Everyone taking Squidward to the volcano]
‣ House of Horror - Larry Hochman [Squidward about to be sacrificed]
‣ Drama Link (o) - Hubert Clifford ["It is I who makes Squidward miserable. Throw me in instead."]
‣ Dramatic Bridge 4 - Phil Green ["SpongeBob, help!"]
‣ Dramatic Cue (b) - Ronald Hanmer ["Please, SpongeBob, I didn't mean any of that!"]
‣ Fates - Gregor F. Narholz ["I'm grateful for the life I'm living."]
‣ Red Alert [#8] - Harry Bluestone, Emil Cadkin ["Goodbye, everyone!"]
‣ Horror Crash - Harry Lubin [Squidward falls]
‣ Historical Fanfare [#68.02] - Harry Bluestone [SpongeBob rescues Squidward]
‣ Grass Skirt Chase - Sage Guyton, Jeremy Wakefield [Squidward's house blowing away to the volcano]
‣ Traveling Along in the Key of D - Nicolas Carr, Barry Anthony, Sage Guyton, Jeremy Wakefield [ending]
- This episode is available on the Legends of Bikini Bottom, Complete Seventh Season, and Next 100 Episodes DVDs.
- Although this episode premiered in 2011, it was made in 2010 according to the credits.
- Some episodes are released in a different year than they were produced.
- The idea that a volcano being a threat to Bikini Bottom was later reused in The SpongeBob Musical.
- In the French dub, this episode's title card (along with its sister's) is inside a book titled "Les légendes de Bikini Bottom," which translates to "The legends of Bikini Bottom."
- Mr. Krabs calls the cash register "Cashy" once again. The first time he calls it this is in "SpongeBob SquarePants vs. The Big One."
- This episode first aired with "The Main Drain." Later in a rerun on March 6, 2011, it was paired with "Trenchbillies."
- This episode marks the first time a dolphin in SpongeBob SquarePants actually talks.
- The second is The SpongeBob Movie: Sponge Out of Water.
- When a real underwater volcano erupts, it will create islands and sometimes makes tidal waves.
- This episode premiered eight years after Tales from the Deep, Bikini Bottom Bash!, and Deep Sea Sillies were released and six years after The SpongeBob SquarePants Movie was released in Spain.
- This episode reveals that Squidward's eyes can change color since they turn blue when he imitates SpongeBob.
- This is the second episode where Squidward says respectful words to SpongeBob. The first one was "Fools in April."
- This episode marks the second time someone uses a tape recorder to prove that Squidward said something that he's denying. The first is in "Boating Buddies."
- The person who has the recording tape to record Squidward's voice is the same as from what happened in "Boating Buddies" where he does it to SpongeBob.
- This episode marks the fourth time everyone cheers except for Squidward. The first is in "Texas," the second is in "Squid Wood," and the third is in "Slimy Dancing."
- When SpongeBob asks the mayor about parking tickets, he said he didn't have a car. Boatmobiles are the main transportation, thus SpongeBob should have said he doesn't have a boat. The first time he says "car" is in The SpongeBob SquarePants Movie.
- The Volcano Shelter has a thatched roof, thus it would have burned quicker than the Krusty Krab's wooden roof.
- The volcano is located across the street from the Krusty Krab, which is exactly where the Chum Bucket is supposed to be. Consequently, Plankton, the owner of the Chum Bucket, does not appear in this episode.
- The voice of the slimy trash can creatures aren't listed in the credits.