Gerbilling

Gerbilling, also known as gerbil stuffing or gerbil shooting, is an unsubstantiated sexual practice of inserting small live animals (usually gerbils but also mice, hamsters, rats and various other rodents) into the human rectum to obtain stimulation. Some variations of reports suggest that the rodent be covered in a psychoactive substance such as cocaine prior to being inserted.
Overview.
According to folklorist Jan Harold Brunvand, accounts of gerbilling were first recorded in 1984 and initially were said to involve a mouse and an unidentified man. In subsequent versions of the story, the animal was a gerbil and the story applied to several male celebrities. Rumors surrounding various male celebrities engaging in gerbilling have become persistent urban legends.
As of the mid-1980s, there were no reports in peer-reviewed medical literature describing gerbilling among the variety of rectal foreign objects removed from people's bodies.
Mike Walker, a "National Enquirer" gossip columnist, spent months attempting to verify the gerbilling rumors about a celebrity. "I've never worked harder on a story in my life," Walker told the "Palm Beach Post" in 1995. After much investigation, he was unable to find any evidence that a gerbilling incident ever happened: "I'm convinced that it's nothing more than an urban legend."
Dan Savage, a sex-advice columnist who frequently discusses unusual sexual practices, stated in 2013 that he has never received a first-hand or even a second-hand account of the practice.
According to the editors of Snopes.com, gerbilling is an unverified and persistent urban legend.
In the song "Fack" from his 2005 album "", rapper Eminem recites a verse about gerbilling. "Now see that gerbil, grab that tube/stick it up my butt/let that little rascal nibble on my asshole".
National Lampoon's Christmas Vacation (1989) includes a scene where the character Eddie refers to gerbiling. He says (speaking to his wife): "Don't forget the rubber sheets and gerbils". 
A February 2015 episode of "Family Feud" featured a woman who immediately answered "a gerbil" when host Steve Harvey asked "Name something a doctor would pull out of a person." The response produced prolonged laughter from the audience and a stunned silence from Harvey; even the other contestant at the podium burst out laughing over her response. The clip of the scene from the episode quickly went viral.
In their song "Ich Tu Dir Weh" from the album "Liebe ist für Alle Da", the German metal band Rammstein refers to this practice: "Wünsch' dir was ich sag' nicht nein / Und führ' dir Nagetiere ein." which translates into "What you wish, I don't say no / And insert rodents into you." Furthermore, while performing on stage, the band's singer Till Lindemann occasionally resorts to suggestive gestures that make the meaning of the lyrics quite explicit.