The Three-Boobed Girl
In the middle of September 2014, Jasmine Tridevil, who's real name is Alisha Hessler, became an internet sensation after tweeting and posting videos and pictures of herself with what appeared to be a third breast on her chest. She claimed she got the surgery done in an attempt to get her own reality show on MTV.
Her first tweet was on August 15th, and her most retweeted tweet was on September 15th which is when it seems the hoax was gaining the most steam. It didn't last for very long though because on September 23 multiple articles were written with interviews from real plastic surgeons who basically stated that a third boob was possible but wouldn't look anything like Tridevil's photos.
On the same day a police report was made public that stated that Tridevil had been the victim of a theft. A duffel bag that belonged to her had been stolen, the report lists all the items that were in the bag and one of them was a 3 breast prosthesis. So the hoax basically lasted for a little over a month, or 44 days to be exact.
Here is a link to her massage website, where she states she is a "provider of internet hoaxes since 2014"