What is the name of the perpetually dirty Peanuts character?

Pig-Pen is the perpetually dirty Peanuts character.

Pig-Pen is famous for the cloud of dust and dirt that follows him wherever he goes. His nickname refers to his permanently grimy appearance, especially his filthy clothes and overalls. Although he is usually cheerful and good-natured, the other children often comment on his condition or treat his dirtiness as a source of comedy.

Charles M. Schulz introduced Pig-Pen on July 13, 1954. The character's defining joke is not simply that he refuses to wash: Peanuts often depicts dirt as something that seems mysteriously attached to him. In one memorable type of gag, even bathing and putting on clean clothes fails to keep him clean for long.

The name is also easy to misremember. Through 1980, Schulz generally wrote it as “Pig-Pen,” with a hyphen; from 1981 onward, the spelling was usually “Pigpen.” Rerun is a younger member of the Van Pelt family, while 5 is a character whose name comes from his father's choice to replace family names with numbers. Neither is associated with the famous dust cloud.