Okay, first we'll preface this story by saying it took place a couple of years ago, so the mini-monster in question is probably long dead. But that doesn't make the circumstances any less horrifying... because it happened for real, and that means it could happen again.
Back in 2011, a worker in a large supermarket in Bexbach, Germany was going through produce stock when he saw a huge, gray, hairy spider jump out from a banana crate. According to German news agency Spiegel, the employee first assumed the eight-legged beast was a banana spider, which is a common and mostly harmless orb-weaver variety. But when he did some online searching to determine the exact species of the creature, he was horrified to discover it matched the image of the Phoneutria nigriventer, or Brazilian wandering spider ... an extremely aggressive species whose bite is considered the deadliest in the world.
The resulting scare led to a total shutdown and evacuation of the market so the spider could be contained, and local authorities and arachnid experts from the local zoo were called in to assist. To make matters worse, the wandering spider is a nocturnal hunter, so much of the search had to take place in complete darkness. The entire store was treated with pesticide... but the spider was never found.
Again, this took place quite a while ago, so this particular monster is probably long dead. But next time you go shopping, you might want to think twice before grabbing that perfect bunch of bananas...