Plot Synopsis
The book starts with the protagonist, Ricky Beamer, recounting why he has sneaked out of his house to play a trick on the school newspaper editor, Tasha McClain. Ricky left his house at night while his parents were busy to plant a "hilarious" item in the forthcoming edition school newspaper, "calling all Creeps" to call Tasha after midnight. Ricky waited outside the classroom window until Tasha left to go to the juice machine and typed it on the front page of the paper.
The reason Ricky gives for doing this is that Tasha called him a "creep" and kicked him off the newspaper staff when he accidentally threw a can of Pepsi all over her computer.
There's a reason as to why he's not really at fault, because of the actions of a quartet or Ricky's enemies, helpfully identified numerous times as "My Enemies" by Ricky. Jared, David, Brenda, and Wart, makes sure Ricky is receiving 100% of the entire student body's allotted bullying. For instance, it was Wart's fault that Ricky threw a can of soda. Later, when Ricky is given a second chance to get back on the paper, it's Wart and his friends who spray the camera Ricky was using to photograph a school car wash, ruining it.
Ricky is taunted by everyone in school at some point with either "Sicky Ricky" or "Ricky Rodent." All this is even worse than normal for Ricky thanks to the new girl at school, Iris, who likes him for some reason, and who he is continuously embarrassed in front of. At one point Wart forces him to sing The Star-Spangled Banner in front of her.
So Ricky's gotten back at Tasha, and he calls Iris to gloat, but she suggests that maybe things will turn out badly for Ricky with this prank. Things do turn out bad, because Tasha caught Ricky's addition and changed it to "Call Ricky After Midnight if You're a Creep."
Ricky starts to get calls after midnight from breathy voices identifying themselves as Creeps, asking when they can meet to discuss "the planting of seeds." Ricky tells Iris about the troubles he's having, and she suggests disconnecting his phone. Iris asks if Ricky would help her go shopping for baking supplies, as the school bake sale is coming up and she wants to make something really nice to make her mark on the school.
Ricky intends to meet her after school to go grocery shopping, but he gets sidetracked by monsters that kidnap him. His four enemies grab Ricky and drag him into the woods. They identify themselves as Creeps and call Ricky their Commander. They apologize for having teased and bullied him earlier, for they did not know until they saw the announcement in the paper that he was the Commander of the Creeps. Then the four kids change into the reptilian creatures on the book cover. They tell Ricky that their mission must come to fruition soon, their mission of changing all the kids in the school into Creeps by having them ingest "Identity Seeds." The Creeps insist that they are superior to humans, which the Creep-Wart proves by swallowing a squirrel whole.
One of the Creeps holds up a bag of Identity Seeds, which look like chocolate chips. Another of the Creeps tells Ricky that they have a plan and with the Commander's approval they will implement it. The plan is to stir the seeds into the food in the lunchroom. That superior to humans argument is looking a little more specious, but Ricky tentatively agrees to it.
Ricky arrives at school early the next day, after his attempts at eliciting help from his principal and parents fail. He tells the Creeps not to go through with it, but they insist. They give Ricky the bag of seeds and he first pretends to trip and spill all of the seeds everywhere in the cafeteria kitchen. One of the Creeps tells him not to worry; they always keep a spare bag of Identity Seeds around. Ricky gets an idea and stirs the seeds into the macaroni and cheese, a dish he knows no one on the school eats. After no one changes into Creeps, Ricky apologizes for the plan's failure.
That's okay; the Creeps have another plan. They'll bake the seeds into chocolate chip cookies and give them out for free at the school bake sale. Since it only takes eating one seed to make a human a Creep, and no one can resist free cookies, everyone will be a Creep, they reason. Ricky tries to backpedal out of agreeing to the plan, and the Creeps turn on him, doubting he is their commander. This is when Iris barges in, announces herself as the Commander's Sergeant, and tells the Creeps that they will go ahead with the bake sale idea.
Once the Creeps have left, Iris tells Ricky she's not really a Creep, but that she had followed them the afternoon that Ricky didn't show up to go shopping, and had seen and overheard the whole exchange, so she waited until the next day to talk about seeing the boy she liked surrounded by villainous monsters.
At the bake sale, Ricky tries to think of a way to stop people from eating the cookies. His solution: grab a megaphone and tell everyone not to eat the cookies or they'll turn into monsters. Somehow this plan doesn't work, and the student body throws food at him, taunting him, mocking him. Tasha shows up to make fun of him personally. The Creeps corner Ricky, ask why he isn't handing out the cookies. They tell him that once they all turn into Creeps, they'll become his slaves. Ricky considers this, and then personally hands a cookie to Tasha, followed by the rest of the student body, and even one for himself.