It's the 1890's, and American author Mark Twain is lounging on a beach in Ceylon (now known as Sri Lanka), which is currently under British rule. He's sitting on the beach contentedly working on notes for his book Following the Equator, when he feels a gentle poke in his back and a tickling sensation. At first it's just the giggles. Soon he's doubling over, laughing uncontrollably. Unable to reach whatever it is that's affecting him, the author of Huckleberry Finn is choking and gasping with laughter, on the verge of passing out, when a ten year old boy pulls the animal off him and probably saves his life.
At first, Twain couldn't figure out why the creature had tickled him. Why had it pressed its snout against the middle of his naked back and sucked gently? Twain's experience was actually not unusual. Each year there were a number of unexplained deaths on the beach, and local signage (which unfortunately Twain hadn't paid attention to) warned sunbathers to be on the lookout for a local Badger coming out of the nearby forest to tickle the tourists and unaware locals. Twain quickly penned a humorous short story based on his experience called The Hop-a-Long Pinnochio Badger, which he read at local British tea rooms across the nation on his travels. The name stuck. Unfortunately, the story didn't; Twain forgot the original draft in his hotel room when he boarded his steam ship and left the island. The story was never recovered.
The tickling sensation that Twain described actually comes from the creature sucking salt from the victims body. The minerals in the salt are one of the creature's primary nutrients. While the Badger can and does get its nutrients by drinking and expelling sea water, attaching itself to a warm blooded creature is its preferred method of eating. For most people this is simply annoying and perhaps a little disgusting; they just roll around on the sand until the creature disengages. But for a small percentage of the population, the creatures suction cup stimulates a nerve cluster in the lower back that leads to an uncontrollable tickling sensation. The giggle response is so strong that some people can end up literally choking to death on their own laughter.
The Hop-A-Long Pinnochio Badger doesn't actually hop - that was apparently one of the jokes of Twain's story. However, it does appear here and there in literature and art. In addition to Twain's story, Star Trek: The Original Series notably used the Hop-a-Long Pinnochio Badger as the basis for an alien life form that feeds on salt in the episode, The Man Trap. Virginia Woolf's husband Leonard lived in Ceylon for many years and told her many tales of his time there; she eventually wrote The Mark on the Skin, which is a lyrical prose poem of a story that describes a woman's stream of consciousness as she dies laughing from a Pinnochio Badger bite. Some scholars have theorized that it was Woolf's way of begging her husband to shut up and stop telling her about Ceylon - the "badger" in the story is actually a metaphor for her husband.