1. The Potion Master
"My younger cousin likes to make 'potions,' which are just a bunch of random foods cooked together on the stovetop. One time, he got really adventurous and mixed butter, spices (like garlic powder, cinnamon, lemon pepper), orange juice, water, Pam, a raw egg, his antibiotics, ketchup, mayonnaise, and probably a lot more stuff that I'm missing. It was, without a doubt, the WORST thing I have ever smelled. It smelled so bad that he started puking and crying, and no matter how many fans we turned on and windows we opened it wouldn't go away. We had to leave the house for a while."
—Josephine Rose Gilchrist, Facebook
2. The Beached Whale
"On a scenic train trip for my honeymoon, the conductor announced that we were passing by a beached whale visible from the train. The wording he used implied it was still alive, so I joined a bunch of other people out on the open-air viewing car. I'd only ever seen whales from a distance, and thought it would be cool to see just how big they really are. But alas, the whale was dead. So very, very dead. It had probably been dead for some time before landing on the beach. The moving train we were on was easily 500 meters away from this whale and still the stench hit us like a ton of bricks. It smelled like the arsehole of Satan himself. I threw up over the side of the train, and the woman next to me dropped her iPad. Other people were retching and there was a jam of people rushing to get back into the closed carriages of the train."
—Kathleen Brooking, Facebook
3. The Overly Generous Dog Treat
"When I was in high school, my boyfriend had a young German shepherd–husky mix. For some reason, he decided one day to present the dog with an ENTIRE bag of pig's ears. The next day, I went to his house on my lunch hour and when I got to the front door all I could smell was crap emanating from inside. I opened the door and was slammed in the face with the smell. I managed to take one step and all I could see was explosive dog diarrhea all over the carpet, walls, and CEILING of his living room. Needless to say I backed away and refused to go back into that house for a couple weeks. AWFUL!"
—Anna Murray, Facebook
4. Crabplosion, Version 1
"My husband was in a marine biology class. He brought home a crab for preservation and forgot to pour formalin in the jar. The gasses of the decomposing crab built up and blew the top right off the jar. The amazingly disgusting odor of rotting sea creature permeated the house at once. Nauseating!"
—Lana Creer-Harris, Facebook
5. Crabplosion, Version 2
"I used to work at a grocery store. One day, the people who worked in the seafood department found a very, very old canister of crab meat. But here's the thing: This can was also, like, bloated, with a big bulge in the metal. As the manager was explaining how to dispose of it, this woman who was always in the wrong place at the wrong time came along with a barbecue fork and punctured the can. This horrid red-brown liquid started shooting out, not unlike when you shake a soda can and open it.
"The smell was putrid. It was horrid. The whole store smelled it within a matter of minutes. The worst/best part is that it spewed all over the woman who popped it. I still gag on the rare occasion that I think of this."
—Miguel Portela, Facebook
6. The Lightly Sautéed Cat Pee
"If you want to know what hell smells like, get a cat who pees on an electric stove while no one's looking. Go ahead and turn the stove on to make dinner, and experience the 10th circle of hell: burning cat piss."
—Allis Valentine, Facebook
7. The Protein Shake
"I left a protein shaker, coated with the remanence of Big Train Mocha Frappuccino protein mix, in my Jeep for over 10 days. In the sun. It had rolled under the seat and I'd lost track of it.
"When I finally found it and opened it, the unmistakable, permeating stench of reeking shit filled the entire house. It took three days to get the smell out of THE AIR. We had to replace our air filter."
—Tanner Campbell, Facebook
8. The Rotten Whirlpool
"Our fridge broke and the delivery for its replacement kept being delayed, so while we waited for our new unit we packed the essentials in a cooler and left everything else to rot. When we finally got our new fridge a couple weeks later, we went about throwing away all the old food, which included a jar of kimchi, but my dad wanted to save the glass jar it was in. I begged him not to open the jar and just throw it out, but he was adamant about saving it. So he dumped all the hot, bubbly contents down the drain and ran the garbage disposal for a solid minute, creating a rotten kimchi whirlpool. I can't even begin to describe the smell that rippled through the air. I wasn't a huge fan of kimchi before this, but that smell sealed it for me."
—Jeremiah Rosen, Facebook
9. The Triple Threat
"My dog likes to eat out of my cat's litter box when I'm not paying attention. The problem is, this upsets her stomach (for obvious reasons). She will then vomit a foul concoction that casts the smells of puke, cat poop, and kitty litter throughout my house. I will never be able to forget that rancid smell until the day I die."
—Stephanie Dudak, Facebook
10. The Mysterious Earth Melon
"The worst thing I ever smelled? A watermelon that had been buried underground for who knows how long."
—Jebadiah Jackson, Facebook
11. The Glug
"One night, as I was watching TV with my boyfriend, we heard a glug noise out of nowhere. We got up to investigate, but got no further than the living room's threshold when the smell hit our nostrils. Nothing can ever prepare you for a smell of that sort; it was sour, rotten, and burnt. Eyes watering, we made it to the bathroom only to find the tub's drain spewing dark brown sludge, Nightmare on Elm Street style. We, along with the rest of the apartment building's inhabitants, had to evacuate. Many were vomiting, kids were crying, and some had called the police. We later found out that sewer line for THE ENTIRE BLOCK had backed up into our building. We had to shower at a truck stop for a while, because we couldn't bring ourselves to go back into the bathroom."
—Stephanie Harry, Facebook
12. The Ol' Rat-in-the-Dog
"There was a rat in our laundry room. I put down poison. The rat ate the poison, crawled outside, and died in the front yard. A couple days later, I let the dogs into the front yard, and my much-beloved beagle found the putrefying rat and ATE IT. Since I knew the rat had been poisoned and that the poison would affect the dog, I immediately induced vomiting. We were out of ipecac, but that's OK, because there are other common household substances that will induce vomiting. Like watered-down yellow mustard.
"It worked. She puked up everything in her stomach. Everything.
"Now image that scent. A top note of sharp, eye-watering mustard. Beneath that, the intense, competing aromas of bile and decomposition, like shit and puke and death had a terrible threesome and this was their awful stank-baby. Add just a hint of rodent-y musk, and the undertone of mostly digested dog food."
—Anissa H. Roy, Facebook
13. This UNSPEAKABLE HORROR
"Walking into your parents' bedroom right after they had sex…worst smell ever."
14. The Rock Star Stench
"I used to be a guitar technician who toured with rock bands. It was my job to tune the guitars every day and keep them in good shape. At the start of one particular tour, I picked up one of the performer's guitars for the first time and was like, 'Hey, what's that funny smell? Is it coming from the guitar?' Then I leaned in and smelled the strap. Whoa boy, that stench.
"I soon found out that this strap hadn't been washed in 10 years. Ten YEARS. Imagine the sweat of a thrash metal rock star getting sponged up by the strap for 10 years. And now also add on the fact that we were touring for six weeks in a row and I had to hold and tune this guitar every single day..."
—Twiggy Demaio, Facebook
15. The Queasy Mac
"I was cooking Easy Mac in my microwave, and after two and a half minutes I began to smell this terrible stink. When I opened the microwave, I found that I had forgotten to put water in the bowl and had just been nuking dry pasta.
"The pasta was black and stuck to the bowl, which I had to chuck out, and to this day I can still remember that stench. I still haven't smelled anything worse."
16. The Green Bacon
"My grandma once lovingly fried up some rotten bacon. It was grayish green, sizzling away in the pan. My whole family ran out of the house gagging. It was literally hours before the smell dissipated enough that we could go back in. I had to throw away all the clothes I had been wearing while she was cooking."
18. Lilo & Stench
"There is a Lilo & Stitch ride at Disney World that sprays some disgusting, vile-smelling stuff in the middle of the ride. And it is the most horrible thing I have ever smelled." —sallyrs
"THE LILO & STITCH RIDE AT DISNEY WORLD IS DISGUSTING." —oliviam480cfbbed
"I still remember the fucking smell of the Lilo & Stitch ride to this day and it haunts me." —camitellezdlm
19. The Liquid Ass
"In high school, my boyfriend bought this prank spray called Liquid Ass and even one squirt of it was heinous. One day, we were driving in my car and the bottle accidentally shattered, filling the small space with what I can only assume to be the stench of one thousand liquified asses. Needless to say, we were both dry heaving out of the windows for the rest of the ride home. And yes, we are still together and I never let him forget that moment."
20. The Ancient Dentures
"After my grandfather died, we worked with my grandmother to clean up and sort his stuff. While we were cleaning their closest, a jar containing my great-grandfather's dentures fell out and broke. The dentures and the liquid in the jar were more than 40 years old. It smelled like a burnt, mildewy corpse."
21. And finally, the most popular response by far, with over a dozen mentions in the comments: ROTTEN. POTATOES.
"A mystery stench had been permeating my family's kitchen for over a week, and no matter how hard we searched, we could not find the source. One day, when my sister and I were home alone, we realized we hadn't checked behind our freestanding pantry. As my sister pulled the pantry from the wall, a large bag of red potatoes tumbled down from the top of it, bringing a trail of gelatinous black goo down with it. The rotten potatoes exploded upon hitting the floor and a most putrid smell filled the entire house. My sister and I wretched and cried. She may have vomited. It's all a blur."
—Mariel Paré, Facebook
Who knew spuds were capable of such evil?
Note: Submissions have been edited for length and/or clarity.