Mrs. Puff

"Why can't you just graduate out of my life?"

- Mrs. Puff

Mrs. "Poppy" Puff is a recurring antagonist in SpongeBob SquarePants.

She is SpongeBob's boating school teacher, and with each episode, she grows more and more hateful (and afraid) towards him, even developing somewhat of a phobia. This is most likely due to years of having put up with SpongeBob's failures and the trouble he has caused. However, considering the fact that she has yet to outright tell SpongeBob that she dislikes/hates him, or that he is a terrible driver who will never get his Driver's License, her suffering is arguably partially her fault (though it is still largely SpongeBob's).

Villain Side
Her two most notable antagonistic actions were seen in the episodes No Free Rides and Demolition Doofus. Coincidentally, both involved her tricking SpongeBob into believing her schemes were extra credit.

No Free Rides
""I've got to end this thing before it begins"."

- Mrs. Puff realizing her mistake about passing Spongebob.

Mrs. Puff passes SpongeBob from her class just to be rid of him for good. Afterward, she feared that SpongeBob would destroy the town because of her mistake. Later she snuck into SpongeBob's boatmobile and drove off with it, unaware that her student was sleeping in it. The two get into a fight and SpongeBob eventually discovers who the thief was. The boat crashes into a police car and Ms. Puff ends up in jail.

In that episode, it was also revealed she had formerly moved from another town and changed her name. It could be due to criminal history, or otherwise another unfortunate mishap related to her.

The Bully
Though in this episode she didn't do any villainous deed, she somewhat still antagonistic much like other 2 episodes by oblivious with Flatts' intention to harm SpongeBob. Even when she saw SpongeBob taugh his classmate about lesson regarding violence after endures Flatts' attacks that miraculously not harmed SpongeBob and causes Flatts himself passed out, she attacks him anyway.

New Student Starfish
Although she didn't do any villainous deed, she acted antagonistic when she warned SpongeBob and Patrick to pay attention. She also removed one of SpongeBob's good noodle stars after discovering that SpongeBob wrote "Big Fat Meanie" to her, even though it was actually Patrick who wrote "Big Fat Meanie" and sends SpongeBob to the back of the room. She also confronted SpongeBob and Patrick for fighting in the halls and sends SpongeBob and Patrick to detention. She later redeems herself and gives SpongeBob and Patrick each good noodle star for saving Roger.

Demolition Doofus
""Why are you still ALIVE!?""

- Mrs. Puff's infamous quote from the episode.

After one of SpongeBob's failed attempts at driving, her inflation sac is ruptured and she was told she could no longer inflate, resulting in her hatred of SpongeBob to skyrocket. While at the hospital, she sees injured demolition derby drivers and enters SpongeBob in the annual demolition derby, hoping he would die in desperation to get SpongeBob out of her life. However, much to her displeasure, he survives thanks to his reckless driving, and becomes a star. She then snaps and crosses the Moral Event Horizon by driving a large monster truck and attempting to murder SpongeBob herself. She then regains both her sanity and puffing ability, however, by crashing into her boating school.

This episode is what many fans of the show consider to be her darkest role. This is what cemented her status as a villainess, as she wanted SpongeBob out of her life so desperately, to the point that she was willing to murder him in order for that to come into fruition.

Trivia

 * Ever since the beginning of the series, Mrs. Puff has had her own criminal record, which explains her being arrested a few times. Such as ditching jury duty or littering, but mostly for Spongebob's wreckless driving and being blamed for it, because it was implied by an officer that driving teachers in Bikini Bottom are held responsible for that sort of thing.
 * She is one of the few characters in the series to cross the Moral Event Horizon, along with Mr. Krabs, Plankton, Patrick Star, and Squidward.
 * It is possible that should she be unable to re-inflate, she immediately prone to insanity, which explained her murderous rage towards Spongebob. And when she regained her ability to inflate, she regained her sanity as well.