Sex Maniac was arguably the first character in Viz magazine to achieve UK-wide notoriety, and was certainly on a lot of teenagers' T-shirts in the late 1980s. He is, on the face of it, an ordinary boy; except that he suffers from extreme, excessive flatulence which is not only offensive to the nose and ears, but destructive to those around him. His gaseous emissions have been known to destroy houses and other hard-surfaced articles, as well as injure people. He is always apologetic, and constantly reminds people that his colonic expulsions are beyond his control -- despite his insistence on "keeping to a strict pump diet," which often includes beans and "cabbage water."
A similar device was used in the cartoon strip "Little Sammy Sneeze", where the disruption is caused by the character's sudden explosive sneeze rather than flatulence, by cartoonist Winsor McCay in 1904.
The strip was seemingly retired after creator Simon Donald left Viz at the end of 2003; between then and 2007, he only made two, brief appearances in the comic. However, in the March 2007 issue he reappeared in a topical strip where he was hired by "Matthew Bernards," first to use his farts to flavour the company's products, then to gas their turkeys after an outbreak of avian influenza was discovered. He also made an appearance the following month.
Johnny also has a French pen-friend with a similar flatulence problem, appropriately named Pierre Pumpytrousers, as well as a German named Hans Honkyhosen.
In Viz 166 (June/July 2007), Johnny was forced by his father to attend a lecture on global warming, presented by none other than Al Gore, so that he would learn about the impact his farting was having on the environment. When Johnny intentionally farted during the applause for Gore (so that nobody would hear it), the former Vice President became violently ill, causing Johnny to observe that Gore was now "greener" than his environmental message.