The cadets that are seen include (from left to right):
A male purple fish.
A female light blue/green fish who is thin.
A very short male brownish yellowish fish.
A tall male yellow fish.
And a tall female pink fish (who is about the same height as the male yellow fish).
The Milkshake Academy Cadets are skilled, unlike SpongeBob. They are able to perform any task Captain Frostymug tells them to do with ease. They are first seen just outside the Milkshake Academy jogging with large jugs of ice cream on their backs. When Frostymug singles SpongeBob out asking what he was holding (which was a ice cream scooper), SpongeBob said it was an "ice cream spatula" and all five of the cadets laughed at SpongeBob. Frostymug then tells a short story on how he is going to turn them into milkshake machines and tells them to get to their milkshake stations. All five cadets are successful at bending up a milkshake but SpongeBob isn't too lucky as he doesn't know where the control panels are. Frostymug then has the purple cadet tell SpongeBob where the real controls are. SpongeBob then blends up a milkshake, although, it ends up smashing into Frostymug's eye. The Cadets then follow Frostymug into the Shake Simulator room where he decides to put SpongeBob into the machine. Frostymug sets it to the highest setting much to the horror of some of the cadets. SpongeBob ends up having fun in the machine greatly upsetting Frostymug. Frostymug then loses it and asks the cadets if they have any tips to teach SpongeBob. The shortest cadet implies that Frostymug is better off "teaching a hunk of coral." All five cadets laugh and SpongeBob storms off saying he will show them. The cadets are then put through a series of tests including cherry shooting range and even volleyball. They all managed to complete their tasks but SpongeBob was once again unsuccessful in doing this. The Milkshake Academy Cadets are seen for the last time at a milkshake ceremony as Captain Frostymug hands them all their milkshake licenses. They all leave the Academy excited to be qulified milkshakers but SpongeBob is left without one of his own (though he did receive one at the end).
Out of the five cadets, only three of them have speaking lines in "License to Milkshake."