It's every man's worst nightmare.
Zhang Nan, of China, was bathing with live eels in order to cleanse his skin when things went horribly wrong. According to Metro, one of the small eels managed to not only swim up his urethra, but actually made it all the way to his bladder.
"I climbed into the bath and I could feel the eels nibbling my body. But then suddenly I felt a severe pain and realized a small eel had gone into the end of my penis," the 56-year-old told the British paper.
The eel bath is similar to more common "fish pedicures" in which small sea creatures remove layers of dead skin.
Nan was rushed to the hospital where a three-hour operation removed the slimy little menace. Metro reports that by the time the eel was extracted, it was already dead.
Strange as it may sound, it's actually not the first time an aquatic animal has made its way up a man's urethra. In fact, there's an entire episode of "Jeremy Wade's River Monsters" dedicated to a fish that is infamous for such incidents.
The Candiru catfish, a vicious Amazonian species, uses its slimy nature, much like the eel, to penetrate the human body. Wade details the excruciating event in the clip below.
WATCH (Jeremy Wade's tale of the Candiru swimming up a urine stream):