What has eight legs, venom that dissolves human flesh and a habit of hiding in clothes?
It sounds like a malarial fever dream, but scientists have discovered a spider in Mexico with venom so potent, it rots human flesh.
AKA a traveller's worst nightmare.
While a bite is not necessarily fatal, they can leave 40cm lesions of dead tissue around the puncture.
The only thing more scary is where the scientists found it. The spider was discovered living in household upholstery and discarded clothing in central Mexico.
Researchers from the National Autonomous University of Mexico (UNAM) first found the spider in the city of Tlaxcala, though it is thought to live across the Valley of Mexico region.
They have given it the proper name Loxosceles tenochtitlan.
Talking to local media about his frightening discovery, Professor Valdez-Mondragon said although the spider doesn't actively seek out human flesh it will bite when threatened.
"We provide them with the temperature, humidity and food to establish themselves in our homes, which puts us at risk of having an accident with them, although they also perform an important ecological function when feeding on insects," He said.
The best way to avoid being bitten is to keep a tidy house and remove possible hiding spots.
If there was ever a reason to stay on top of your housekeeping, this is it.
While most bites are not fatal they can lead to lasting tissue damage, and in some cases organ failure.
"The critical stage is the first 24 hours, and sometimes up to 48 hours when you begin to see the effects. The reaction begins with a sore that expands and produces a quite considerable tissue necrosis [or death of tissue] ," says Professor Mondragón told the Yucatan Times.
There is currently the only one anti-venom available and - at a cost of 16,000 pesos or $1200 – is likely to gouge you as much as the spider's corrosive venom.
Like something out of a horror movie, the spiders rarely emerge from their hiding places - coming out only to feed or look for a mate.
During storms and wet weather the Males are known to scuttle about in search of females, but can take up temporary residence in cloth, furniture and bed sheets.
And it doesn't care who's in there already.