Village idiot

For the 2012 Andreas Johnson album, see Village Idiot (album).
De idioot bij de vijver (The Idiot By the Pond, 1926, Frits Van den Berghe)
Bronze statue of Milyo, a "village idiot" of Plovdiv

The village idiot is, in strict terms, a person locally known for ignorance or stupidity but is also a common term for a stereotypically silly or nonsensical person or stock character.