- SpongeBob SquarePants
- Squidward Tentacles (cameo; tentacle only)
- Eugene H. Krabs
- Captain Frostymug (single appearance)
- Incidental 40
- Incidental 41 (cameo)
- Incidental 48 (cameo)
- Incidental 105 (cameo)
- Incidental 42 (cameo)
- Fred (blue) (cameo)
- Incidental 14 (cameo)
- Incidental 106 (cameo)
- Incidental 64 (cameo)
- Incidental 108 (cameo)
- Incidental 104 (cameo)
- Incidental 92 (cameo)
- Sandals (cameo)
- Incidental 60 (cameo)
- Incidental 45 (cameo)
- Incidental 31 (cameo)
- Incidental 46 (cameo)
- Incidental 27 (cameo)
- Incidental 107 (cameo)
- Incidental 73 (cameo)
- Incidental 47 (cameo)
- Milkshake Academy cadets (single appearance)
- King Neptune (mentioned)
One day around lunchtime, while working at the Krusty Krab, SpongeBob gets a last minute order to serve a milkshake, which he has not made in years. SpongeBob decides to make a simple milkshake in a blender and finishes it off by topping whipped cream and a cherry while walking out of the kitchen door. He serves it to Harold. Then, Harold says it tastes horrible and throws a temper tantrum, demanding a refund while angry. Mr. Krabs comes in and walks Harold out of the restaurant while telling him that SpongeBob will make a proper milkshake for him tomorrow. It is then revealed that SpongeBob's milkshake license expired seven years ago. Mr. Krabs then puts SpongeBob in a boatmobile and says he is taking him back to school.
SpongeBob and Mr. Krabs later arrive at the Milkshake Academy and SpongeBob has to attend the academy to learn how to make a proper milkshake again. Captain Frostymug tells the cadets to man their milkshake stations. When SpongeBob mans his station, he realizes that there are more buttons and contraptions than he is used to, but thinks he still can make a milkshake with no problem. Later, when he tries to mix the milkshake, he repeatedly pushes the wrong button. Frostymug comes over and has to inform SpongeBob that the controls are different and he has to push the button on the lower control panel. When SpongeBob manages to finally mix his milkshake, he lets Frostymug try it. However, when he tries it, the milkshake is frozen and it ends up in his eye. Frostymug suggests they need to get back to the basics. He tells SpongeBob that before he makes a milkshake, he needs to know what it feels like to be a milkshake. He makes him go into the Shake Simulator, which shapes cadets who enter it into a milkshake-shaped blob. Frostymug sets the Simulator on "Obliterate," which makes the students gasp. A cadet reminds him that no one has ever survived Obliterate, to which he responds that he needs to learn. The simulator shakes, rattles, and rolls SpongeBob. Captain Frostymug decides to see how SpongeBob turned out and gets angry when he sees that he survived, was unaffected, and actually found it fun, believing it to be a fun carnival ride and asking to go again.
Angry, Frostymug says that he has never had such an "unteachable moron" in 30 years. He asks his students to tell him how he could teach SpongeBob how to make a milkshake. SpongeBob replies that he will show the students that he can make a milkshake properly.
However, during the courses of making a milkshake, SpongeBob fails doing them all. During graduation, SpongeBob expects to get his milkshake license at this event. However, Captain Frostymug gives everyone milkshake licenses except for SpongeBob, since he could not even get past Step #1 of making a milkshake, which was filling the glass with ice cream. SpongeBob tells Frostymug that he will keep trying and heads to the milkshake machine. Captain Frostymug tells him he needs to put the milkshake up to "the spinny thing." Then, he stops, flashing back to 20 years ago.
In the flashback, he was the owner of a milkshake café called Milk Shake. Many customers were excited to have Frostymug's milkshakes. However, when he tried to make a milkshake for an eager customer, he ended up splattering the milkshake all over the store. A bit of milkshake got on the cords that connect to the milkshake machine, destroying it. The milkshake machine squirted out milkshake stains onto the customers, frightening them and ruining Frostymug's career. He informs SpongeBob that he has not touched the milkshake machine in 20 years and gets his hand stuck in the machine. He is about to get his arm and all of him sucked into the machine, but SpongeBob is able to grab and save him. The machine ends up exploding, but Frostymug thanks SpongeBob for saving him. Thanks to the machine incident, Frostymug's arm is hurt. He realizes that he does not need a machine to make a milkshake and tells SpongeBob that a milkshake comes from within the heart.
The next day, at the Krusty Krab, SpongeBob serves Harold a milkshake, which he replies is the best he has ever had. Everyone now wants to buy SpongeBob's milkshakes. Captain Frostymug comes in, requesting a milkshake and gives SpongeBob his new milkshake license to which SpongeBob replies, "If only it were this easy to get a boating license" and ends the episode laughing.
- SpongeBob tries to make a milkshake, but fails.
According to the storyboard, while Captain Frostymug was falling, he was going to make a beard out of whipped cream. This was mostly likely cut to save time. Also, he was originally going to have a red beard instead of a gray beard.
|( ‣ ) Production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• Bikini Bottom Bound - Nicolas Carr, Sage Guyton, Jeremy Wakefield [title card]
• Vibe Q Sting - Nicolas Carr ["Double dip milkshake?"]
• Jovial Pirate's Jig - Michael Bolger, Nicolas Carr [SpongeBob serves the milkshake]
• Credit Card Heaven - Nicolas Carr [cherry on top]
• Tension Bits - Nicolas Carr, Sage Guyton, Jeremy Wakefield [customer tries to drink the milkshake]
• Lopey Sailor's Jig - Michael Bolger, Nicolas Carr ["This thing's frozen!"]
‣ Drama Link (G) - Hubert Clifford ["...seven years ago!"]
• The Krusty Krab Jig - Michael Bolger, Nicolas Carr [Krabs tells the customer to come back tomorrow]
• Hot Steel and Slide Licks 5A - Jeremy Wakefield [Krabs throws SpongeBob into his car]
‣ Yankee Doodle - Larry Hochman [Krabs drops SpongeBob off]
‣ Achievements in Aviation - Anthony W Mawer ["The Milkshake Academy!"]
• Trumpet Call to Arms - Nicolas Carr
‣ Dragon Flight A - Daryl Neil Alexander Griffith [Captain Frostymug jumps out of a plane]
‣ Military Parade (a) - Mladen Franko [Frostymug introduces himself]
‣ Glory Road - Sam Fonteyn [Frostymug explains his purpose]
• Hot Steel and Slide Licks 1A - Jeremy Wakefield [cadets laugh]
‣ Glory Road - Sam Fonteyn ["This, Cadet SquarePants, is your scooper."]
• Lap Steel - Nicolas Carr [cadets run around]
• The Donut Dilema - Nicolas Carr [SpongeBob tries to make a milkshake]
• Battle Field - Nicolas Carr ["Sir, yes, sir!"]
• The Donut Dilema - Nicolas Carr ["How silly of me."]
• Hot Steel and Slide Licks 30 - Jeremy Wakefield [milkshake is frozen]
‣ A Hero's Story (a) - Gregor F. Narholz [shake simulator]
• Hot Steel and Slide Licks 2B - Jeremy Wakefield ["That was fun, can I go again?"]
• Hot Steel and Slide Licks 13A - Jeremy Wakefield [SpongeBob gets embarrassed]
• Dangerous Milkshake Zone - Nicolas Carr, Steve Marston [training montage]
‣ West Point - Larry Hochman [Frostymug giving milkshake licenses]
• Vibe Q Sting - Nicolas Carr ["Um, the printer ran out of ink?"]
‣ Tympup (a) - Sammy Burdson, John Charles Fiddy ["No, you simpleton!"]
• Hot Steel and Slide Licks 8B - Jeremy Wakefield [Frostymug refuses to give SpongeBob a license]
‣ Terror Hunt - Phil Green ["The spinny thing..."]
• Ala Mode - Steve Marston [20 years earlier]
‣ Red Alert [#8] - Harry Bluestone, Emil Cadkin [milkshake machine explodes]
‣ Dramatic End [#49] - Harry Bluestone, Emil Cadkin ["No!"]
‣ Epic Adventure - Dick Stephen Walter ["I'm stuck in the blender!"]
‣ Shock Happening 2 - Harry Lubin [SpongeBob rescues Frostymug]
‣ Legion of Honor [#22] - Harry Bluestone ["I'd like to tell you a secret."]
• Lap Steel - Nicolas Carr ["Not at all."]
• Jovial Pirate's Jig - Michael Bolger, Nicolas Carr [back at the Krusty Krab]
‣ V for Victory - Sam Fonteyn [Frostymug gives SpongeBob his milkshake license.]
• Hot Steel and Slide Licks 17D - Jeremy Wakefield ["If only it were this easy to get a boating license."]
• Hot Steel and Slide Licks 19 - Jeremy Wakefield [ending]
- This episode is available on the SpongeBob SquarePants Vol. 15, SpongeBob, You're Fired!, It Came from Goo Lagoon (Digital), Krabby Days, Evil Spatula, Collection Triple, The Complete Ninth Season, Next 100 Episodes, and The Best 200 Episodes Ever DVDs.
- The song "Milkshake" by Kelis is used in a promo for this episode.
- The episode's title is mentioned when Incidental 40 says to SpongeBob, "You probably don't even have a license to milkshake!"
- SpongeBob's milkshake license was first shown in "Yours, Mine and Mine," in which he presents it to Patrick as identification proof.
- If SpongeBob's milkshake license expired 7 years before this episode premiered, it would have expired in 2005.
- In one scene, SpongeBob makes a Krabby Patty instead of a milkshake. This is similar to "Le Big Switch," in which SpongeBob is unable to make anything other than a Krabby Patty.
- Foreshadowing: SpongeBob does not put the milkshake up to the machine's blender when making one in the beginning, foreshadowing it becoming frozen.
- The fighter jet in which SpongeBob flew on resembles the German World War II fighter: the Me 262, the world's first jet fighter.
- This is the only episode that premiered during the "Back to School with SpongeBob" event.
- The Milk Shake restaurant contains a 1970s dance/party theme.
- This is the first time that a time card is in 16:9 HDTV/widescreen.
- This is the second episode where the time card is not read by the narrator. The first was the "3 Days Later..." time card from "I Was a Teenage Gary."
- This is the second episode where Mr. Krabs and SpongeBob have gotten out of the Krusty Krab using the back door while pursuing on the boatmobile. The first was "Bummer Vacation."
- This is the second episode where a time card goes before in time instead of after in time. The first was "The Monster Who Came to Bikini Bottom."
- A clip from this episode was used during Nickelodeon bumpers in 2013.
- This is the second episode to feature a "training montage" to 1980s-style hard rock music, with the first being "The Way of the Sponge" and the third being "Two Thumbs Down" later in season 9.
- This is a rare episode to focus on a location never featured before or after in the series (Namely, the Milkshake Academy). It is unclear what part of Bikini Bottom this takes place in, or whether it is in Bikini Bottom at all.
- It is also a rare episode to feature SpongeBob as the only non-cameo main character.
- The episode's title references the James Bond film License to Kill.
- The Milkshake Academy references the real life military academy.
- Captain Frostymug mentions "Chinny chin-chins," referencing The Three Little Pigs.
- The training montage is a parody of the movie Top Gun, with SpongeBob riding a motorcycle, flying in a fighter jet, and playing beach volleyball.
- Incidental 40 comments that his shake is disgusting and breaks the table with his solid milkshake. Seconds later, he puts the shake in SpongeBob's hat and smashes it. The shake becomes a viscous liquid within seconds, which should not be possible.
- When the other cadets start running around, SpongeBob seems to be cut off.
- When SpongeBob drinks the milkshake at the beach, he has a milkshake mustache, but when he pours the rest on his head and shakes himself, it disappears.
- In the German dub, the time card is translated incorrectly. On the German one, it says 30 years earlier instead of 20 years earlier.
- When Captain Frostymug gets his arm stuck in the blender, he somehow manages to get both of his legs in the blender seconds later.
- When SpongeBob gives Incidental 40 his milkshake, he has eyebrows. In the next scene, his eyebrows disappear. At the end of the episode, his eyebrows are back.