Mrs. Puff is a main character in SpongeBob SquarePants. She is a paranoid blowfish who teaches a boating class. While SpongeBob can pass her written exams with ease, his nerves get the best of him whenever he is up behind the wheel, causing him to crash during each and every driving test. Mrs. Puff usually ends up inflating (the blowfish's defense mechanism) at the end of each test.