Rat-Man is an Italian comic about an inept superhero of the same name. The comic started out as a parody of Batman, but evolved into having complex continuity. It's also known for breaking the fourth wall, engaging storytelling and Monty Python-style nonsense humor.
Rat-Man's alter ego is Deboroh La Roccia. He lost his parents at the mall and was adopted by Janus Valker. He was originally Rat-Boy (a-la Superboy). He became a superhero to fulfill his fantasy of heroics. He joined the second Secret Squad (the first one was destroyed by a mole) formed by the scientific research centre that Janus works at: Elsewhere. In reality, an evil entity called Shadow tried to manipulate the team to take over 'No Name Country'. However, the Men in Tights, a team that embrace the dogma of the first Double S, clashed with the new team. No Country lost its faith in superheroes. After he quit and the Shadow attacked Janus, Rat-Boy fled to No Name City. He became MarvelMouse. He was forced to compete in gladiator battles. The American-style heroes were dying out and being replace by Manga-style characters. After defeating the "ultimate manga" Dragon, he decided to become a real superhero again. Now as Rat-Man, he became the protector of No Name City and one of the few superheroes left (aside the Double S controlled the Shadow). The Shadow (now controlling the body of Janus Valker) tried to destroy the the second Secret Squad to make a third one. This causes the team is disband thus making Rat-Man the last superhero. Rat-Man in 2003 entered a coma and woke up in 2005, where he has been replaced by a multitude of heroes. He retired and tried to make an animated series whose failure caused him to become a bum. The Shadow tried to make Deboroh his vessel only to be foiled by Rat-Man's friends. Janus manages to overcome the Shadow with the last bit of humanity he has left: the memory of being Deboroh's father. Rat-Man (struggling to become a hero again) goes to New York only find all the villains are gone and the heroes are addicted to their own power. Rat-Man convices them to retire and he returns to No Name City to become a hero again.
My main source was Wikipedia.