Julio A. Serrano (Don Julio) has a degree in Fine Arts from the UCLM. He has worked for El Jueves magazine for fifteen years as a scriptwriter and cartoonist. He has also been a member of the magazine's editorial board and has contributed to other publications such as Retranca and El Estafador.

He has published more than a dozen books in publishing houses such as RBA, SM, Mamut or Fandogamia, among others. He was also editor-in-chief of Makupipe, a digital publisher for children. His best-known works include the history section DesHechos Históricos (Historical UnFacts) in El Jueves magazine, the children's series Cecilia Van Helsing and the controversial activity books for adults Ser fascista está mal (Being a Fascist is Wrong) and El niño Jesús no odia a los mariquitas (Baby Jesus doesn't hate Faggots).

He has made his first steps as a scriptwriter in the audiovisual and video game world. He also teaches comic scriptwriting at Voxel School and La Escuela Minúscula.