Written for The Great Everlasting Prompt Compendium
Prompt 40: Write about an unconventional pet.

A/N: This chapter is dedicated to Chance WrightVA. It was inspired by his Papyrus Plays Bugsnax series. I'm thinking about turning this into a full crossover story, one that tells the story of how Papyrus met the Grumpuses and later traveled to Snaktooth Island with Sans.

For a long time, leaving the Underground seemed like a distant dream, something they could hope for but never truly achieve. Generations of monsters had lived and died in the depths of the Underground, never seeing the sun, never knowing the world above. Therefore, when the dream finally became a reality, it made perfect sense for the monsters to explore the surface world and all it had to offer.

Papyrus, being the young, adventurous type, set out on a journey across the globe, seeing the sights and making new friends along the way. It wasn't until he returned home with one of these new friends that Sans discovered his brother's unusual taste in pets.

"ISN'T HE CUTE, SANS?" Papyrus held up a large cheeseburger, practically shoving the critter in his brother's face. "DURING MY TRAVELS, I DISCOVERED THESE ADORABLE LITTLE FOOD MONSTERS. THIS ONE IS A BUNGER. GO ON, SAY HELLO, SANS!"

"uhhh..." Sans stared at the creature, completely at a loss for words. The cheeseburger was roughly the size of dog, with curly fries for legs and a pair of googly eyes. Curved fries sprouted from its mouth like tusks. And was it his imagination, or was the sentient cheeseburger smiling at him? "lemme guess, you named it patty. am i right?"

The fact that it took Sans a full minute to recover and produce a pun was astounding.

"NO, SANS. THIS IS... WELL, I'M NOT SURE WHAT TO NAME HIM. HE'S A TYPE OF FOOD MONSTER THAT I FOUND ON AN ISLAND IN THE SURFACE WORLD. THE LOCALS CALL THEM BUGSNAX, THOUGH I HARDLY THINK WE SHOULD BE EATING THEM."

"yeah, i don't think we should be eating something that looks like it crawled out of alphys' lab." With a bit of hesitation, Sans reached out and poked the squirming cheeseburger with his index finger. The Bunger let out a cry, wriggling its curly legs. "then again, maybe mettaton could dress it up and use it in his commercials to promote the glamburger."

"OH, DO YOU THINK THAT WOULD HELP ME BECOME BETTER FRIENDS WITH METTATON IF I OFFERED MY BUNGER AS A SPOKESMAN?" Papyrus gleefully shouted, his eye sockets sparkling with joy.

While Papyrus was contemplating the use of his Bunger as an MTT mascot, the food monster was squirming and twisting excitedly in his arms. It had smelled the ketchup stains on Sans' shirt and was frantically trying to get at them, its name escaping in rapid succession.

"uhh, papyrus, i think your burger just went into hyperdrive." Sans took a step back, eye sockets widening, when suddenly the Bunger launched itself through the air, slamming into his chest and knocking the skeleton to the ground.

"NO! BAD BUNGER!" Papyrus scolded. "GET OFF HIM! WHAT DO YOU THINK YOU'RE DOING?!"

But the Bunger wasn't listening. It had latched onto Sans' shirt and was busy sucking the ketchup stains out of the fabric.

Sans groaned, lifting his head off the floor and rubbing the side of his skull. Having only one HP could be such a pain sometimes. Luckily, he wasn't hurt. Just a little dazed from the blow.

"OH MY GOD, I'M SO SORRY, SANS! PERHAPS I SHOULD HAVE WARNED YOU ABOUT BUNGER'S LOVE FOR KETCHUP." Papyrus bent down, taking hold of the mischievous cheeseburger around its waist and lifting it off his brother's chest. Only the Bunger refused to let go. It remained firmly attached to Sans' shirt, sucking and smiling like it hadn't a care in the world.

The sucking continued, accompanied by some wet, slurping noises. Papyrus grunted with exertion, straining until the fabric of his brother's shirt ripped, leaving the Bunger with a scrap of juicy material dangling from its mouth.

"papyrus, please tell me that's the only one of those things you brought home." Sans didn't even want to think about sharing his ketchup with the little monster, let alone an entire pack of ravenous burger buddies.

"OH UHM, YES, WELL I MIGHT HAVE MADE MORE THAN ONE FRIEND DURING MY ADVENTURE." Papyrus stepped aside, opening the front door and revealing a twenty foot tall spaghetti monster looming outside in their yard.

Sans fainted at the sight of it.