Mary Lighthouse was a character in Oink!, 1986-8. When appearing in her own strip, she was drawn by Ian Jackson, however she also often turned up in other strips, drawn by their own regular artists.
Mary Lighthouse was an obvious caricature of decency campaigner Mary Whitehouse, and would often turn up to object to things seen (or promised) in the comic. Sometimes she would even attempt to sabotage the comic, and would get thoroughly humiliated for her efforts.
Although an important and ever-present character in the comic's early days, during its last year the metafictional elements were sidelined, meaning that she appeared only occasionally.