SpongeBob and Patrick go to the Palace of Pranks, a prank store in search of the ultimate prank. To their delight, the manager named Frank sells them a rare can of invisible paint for just one dollar. Before they use it, Patrick remembers that the paint will stain clothes, and then he and SpongeBob take their clothes off so they aren't stained with the invisible paint. They decide to spray a park bench and sit on it, but get in an argument over who gets to spray the bench. During the fight, they spray each other until "several bad puns later," they are both completely invisible.
After asking a man for the time and accidentally scaring him away, SpongeBob realizes that he and Patrick can pretend to be ghosts and prank the whole town. They pretend to be ghosts and go around frightening everyone (moving things around in Sandy's treedome, eating a cake Mrs. Puff was going to eat, painting a moustache on Squidward's face, etc.), until Mr. Krabs, who "ain't afraid of no ghosts," is the last person in Bikini Bottom to be haunted. They attempt to frighten him and succeed until they attempt to burn a dollar bill. Mr. Krabs' fear is overcome by his love of money, and he attempts to extinguish the match with a bucket of water. The invisible spray is washed off of Patrick and SpongeBob, exposing their identities, and their nudity.
Though embarrassed, Mr. Krabs comforts SpongeBob and Patrick by saying he forgives them and was fond of pulling pranks in his youth. However, when they attempt to leave, the Krusty Krab now contains nearly everyone in Bikini Bottom, and Mr. Krabs showcases the "live, nude pranksters." An extremely embarrassed SpongeBob and Patrick try to cover themselves, and SpongeBob says "We should've bought the whoopee cushion!" as the episode ends.
If The SpongeBob SquarePants Movie was the series finale of SpongeBob SquarePants like it was planned to be, then "Pranks A Lot" would have been the last normal episode of the series. However, the series continued after the movie was released.
This is the final episode until "Extreme Spots" to use digital ink and paint.
It is revealed in this episode that Sandy is originally from Austin, TX.
When her escape pod lands it's in the Austin area.
In Spanish, the fish that says "toast" says "Fantasmas," or "ghost," in the Filpino dub he says "gusto nyo?," or "want some?" In the Hebrew version, he says "sandwich"; in Korean, he says "What's that?" in Indonesian version the fish says "Hantu (Indonesian version translated "Ghost")," not "Toast."
Also, SpongeBob didn't say "We'll go spray the park bench and then sit on it." he said "We'll go spray ourselves and let the show begin!"
Sandy's rocket breaks the surface of the water in the Pacific Ocean near the bottom of South America, revealing Bikini Bottom's location, and gives how it can snow in Bikini Bottom because of its location.
The bad puns what SpongeBob and Patrick said while spraying each other with the Invisible Spray was...
"I gotta hand it to you!" Patrick sprayed SpongeBob's right hand.
"Kind of gives you an empty feeling, huh?" SpongeBob sprays Patrick's chest.
"I see what you mean!" Patrick sprays SpongeBob's left eye.
"No guts, no glory!" SpongeBob sprays Patrick's gut.
SpongeBob actually sprayed Patrick in the crotch when he says "No guts, no glory."
Even though most of the words in the newspaper surrounding the article about Mr. Krabs are not real words, the following can be made out: (by line)
On the left-column: "was in," "in the," "can not," "world," "are," skip two lines, "I was in," "in," "I can not," skip two lines, "then he I," "so down I," "happen I," "of the," "said what," "equipped", "then he I", "so down I", "happen I" "way of the", "said what," "equipped," skip two lines, "He I was in," "down in the," "I can not," "of the world," "what are," skip two lines, "He I was in," "down in the," and "I can not."
On the upper column: "So then," skip a line, "it be the way," "and then He I was in So then he said what are," "are in the way of the west," "out their the way of the we how," and "bacon, eggs, and toast. With the same energy" (skip two words) "so is a" (skip one word) "that."
On the bottom-left column: Skip two lines, "and then He I was in," "I wasn't in so down in the," "how did it happen, I can not," "it be the way of the world," "So then he said what are," skip two lines, "and the He I was in," "I wasn't in so down in the," and "happen, I can not."
On the bottom-middle column: Skip two lines, "and then He I," ""I wasn't in so down I," "how did it happen, I," "it be the way," "So then he said what," and "equipped."
On the bottom-right column: Skip two lines "In the door, but I," "he village is so," "not say but how," skip a line, "you are in or out," "much stuff I," "out the disk," "mankind or crab kind" (kind is cut off to only show "ki"), "how," "so is a" (skip a word) "that," skip two lines, "and then He"
On the right column: Skip a line, "I wasn't" (wasn't is cut off to show "wasn'"), "how," "it be," "So the," "boat," skip a line, "I was," "how," "it be," "So," "boat," skip two lines, "in," and "he"
The words "leprechaun" and "hippopotamus" are are also in the article, but they are misspelled.
There is a fan-made Angry Birds comic (Seen here) that used the line, "Ghost! Ghost! Ghost! Ghost! Toast! Ghost!" from this episode.
The episode's name is a pun on "Thanks a lot."
The scene at the Palace of Pranks is a tribute to Pee-wee's Big Adventure, and even uses the "Fake vomit? Real Vomit?" joke from that show.