Its first title was "Mortadelo y Filemón: Agencia de Información". It was just the main characters. Every comics strip had from one to four pages. Throughout the years, the characters have evolved. At first, Mortadelo used to wear a bowler hat. He used to wear some disguises. He was known for his shapeshifter abilities. However Ibáñez went to leave the hat on therefore Mortadelo get disguise inmmediately. The other one, Filemón, called by Mortadelo as ""Jefe"" ("Chief" or "Boss" in English) had a beaked nose and use to smoke pipe as Sherlock Holmes used to do.