Also known as "The Spiders in the Cactus" and "The Spider in the Yucca"
Example:
As told by Ileen Verble:
Here's one my mother told me as breathless fact, claiming she'd "heard it on the news." I knew immediately that it had to be a urban legend, but have never heard it again...
A woman goes to buy a large cactus from a nursery, and brings it home. Later that day she notices something very odd. The cactus appears to be breathing! She calls the nursery she purchased the cactus from and says, "I know this sounds crazy, but I think my cactus is breathing."
The woman she is speaking to tells her to immediately get out of the house, and that she (the nursery woman) is going to call the bomb squad. The bomb squad comes to the house and loads the cactus into a van. Just as they get it into the van, the cactus explodes and out come thousands of scorpions!
It seems that several scorpions had laid their eggs in the cactus, and they all hatched at once.
Example:
As told by Carolyn Lamb:
There was once a lady who lived in a house by herself. She had a lot of potted plants. One day, she noticed that the skin on the cactus in her living room was moving. It gave her the creeps, but then it stopped. She decided she must have imagined it.
Later that day, she was talking to one of her friends. She mentioned how her cactus had been moving. "Oh my god!" said her friend. "Get everything alive out of your house and seal it up. Now!"
The lady was puzzled, but she did what her friend had told her. No sooner had she finished sealing all the doors and windows when the cactus exploded. Thousands and thousands of baby tarantulas came out and filled her whole house.
Her cactus had had tarantula eggs in it!!!
Example:
As told by B.J. Hill:
It seems that a family was given a gift of a gorgeous cactus. (Or perhaps they bought it - I don't know.) At any rate, they took it home and gave it a place of honor in the dining room. (Or sun room or living room...)
They soon noticed an interesting phenomenon - the cactus appeared to be "breathing." In-out, in-out, ever so slightly moved the sides of the huge plant. At first the family thought nothing of it, but then the father or mother or some other responsible soul decided to check it out with the local nursery.
A telephone call was placed and the "breathing" described. The nurseryman shrieked in horror, and told the father (mother, other responsible soul) to "GET THE CACTUS OUT OF THE HOUSE, GET IT OUT NOW!" And Father (or whoever) dropped the phone and complied, racing to get the plant out into the yard.
When he took it outside the cactus EXPLODED and hundreds (thousands, tens of thousands) of baby spiders erupted from the interior of the (now defunct) houseplant.
Analysis: "The Spider in the Yucca," as this tale was known early on, first popped up in Scandinavia during the 1970s and migrated to other parts of the world, including the U.S., soon afterward. The southwestern decor fad breathed new life into the legend during the early '90s, when it also became fashionable to peg Ikea stores as purveyors of the infested houseplants.
The story bears obvious similarities to "The Fatal Hairdo," in which a vain young woman refuses to wash her hair for fear of messing up her towering beehive hairdo (or braids, or dreadlocks in other versions) and ends up with a nest of newly-hatched spiders on her head.
Jan Harold Brunvand covered this urban legend extensively in his 1993 collection, The Baby Train.