Cracker Jack boxes walked so cereal boxes could run. And nothing sold kids on either quite like having a little prize hidden within the sedimentary layers of sugar. Whether printed like a sticker or playing card, or manufactured like a toy car, their inclusion guaranteed sales. And the Winkes cereal company was renowned for having the best prizes.

A glow-in-the-dark alien figure that could stick to the walls, and a candy dispenser shaped like a squatting dog that “pooped” treats, were two of their top cereal sellers. But money has this funny way about it—the more you have, the more you need. So, some bigshot at Winkes came up with the idea to run a localized, small-batch promo.

Of the one thousand boxes produced of their special edition “hearty egg and sausage breakfast” cereal—a testament to the fact that flavor ceased to matter in the age of prizes—only three contained a small egg, secured in protective padding, sealed in a plastic wrapper. The instructions on the back of the cereal box, which appeared beside a cartoon maze, said to place the egg in a bowl of liquid (milk or water would do), and to let it sit undisturbed in the fridge overnight. The true prize would be revealed in the morning.

No one knew where they’d found the eggs, and the Winkes company wouldn’t say, not even when under oath at the trial months later.

A dozen or so of the cereal boxes were distributed daily to each of the three main grocery stores in the company’s hometown. And thanks to international news coverage, wealthy families from around the world flew in to join the hunt. They camped in parking lots overnight and clogged the aisles as soon as the stores opened, tearing boxes off stocking carts long before they could be placed on a shelf. Warring parents would occasionally rip a box in half, both parties dropping to the floor to search the exploded remains for a prize.

After a week of fruitless searching, reporters questioned whether the promo was more ploy than prize. Then a boy of five found the first egg.

With his mother’s help, he placed the unwrapped prize in a bowl of water and left it in the refrigerator, as instructed. The next morning, the boy raced down the stairs with Christmas-level excitement. He delightedly removed the bowl from the fridge, sloshing water over the sides as he walked across the room, then set the bowl on the table, itching to see what surprise awaited him.

The boy couldn’t believe his eyes: A sea creature! A real-life monster! The egg had hatched and dissolved, revealing a tiny grey body. It had a long neck like an elephant’s trunk, a bulbous midriff, a stubby tail, and two large fins per side, where legs might go if it were a land dweller. The boy was besotted.

So at breakfast, when he poured cereal into his own bowl, he poured some into the creature’s bowl as well. After a brief hesitation, the monster lunged for the first piece of cereal, dislodged its tiny jaw like a snake might, and gobbled it up. Reporters were abuzz with the news, playing footage of the cute little thing swimming around, chomping on the sugared bits. They jokingly dubbed it a “Cereal Killer.”

The search for the other two prize boxes grew frenzied, and the discovery of the second egg quickly followed. But no creature emerged in the morning; A devastating loss for the child who could be seen crying on the news. It took another week for the third and final egg to be located. And this one did materialize, looking much the same as the first creature. The little girl, this time—irrationally used as evidence that the company valued equality—was overjoyed.

The promo was considered a great success. Until the boy’s creature, already grown large enough to have taken over their bathtub, bit the boy’s hand clean off.

His parents tried to kill the beast themselves, but its skin seemed impervious, and its size had increased inexplicably post-bite. Animal control was called in to capture and remove it. The PR turned sour. How could the Winkes company have been so reckless? The CEO was fired.

The little girl’s parents were oblivious to those developments. Her creature had grown a bit, needing a mixing bowl instead of a cereal bowl, but she could still eat breakfast next to it. Some cereal for her, and some for the creature—just like the boy had done. It was summer and hot, so her family had plans to go to the community pool. And rather than leave her new friend behind, the girl ladled the creature and some water into a plastic bag, like a goldfish at the pet store, and brought it to the pool with her.

At some point, the creature got loose in the pool and began taking ever-growing bites of the other swimmers, their screams rending the air. By the time emergency responders arrived, the pool was blood-red, and limbs littered the deck. The creature was found in the middle of the road, evidently using its four large fins to waddle toward the lake on the other side. Astonishingly, its body had grown to the size of a firetruck, its neck like an extended ladder. Police opened fire, but rendered no damage or deterrence. They watched helplessly from shore as the creature entered the lake and began eating the boat-cereal sprinkled atop its new, larger bowl.

The town has long since been abandoned, and a billboard was erected to warn travelers. It features a blurred, oversized photo of two shadowed figures with long, hose-like necks peaking menacingly from the depths of the lake, superimposed with a Winkes logo.