Curly Baroque corner fountain in Florence Oltrarno

This amusing fountain, probably 17th or even 18th century, stands on a corner in the Oltrarno near a bus stop I often used at the end of the day to get back to my b&b. Its grotesque mask always made me smile. Its mouth has a metal spout which indicates safe drinking water. The six balls on the escutcheon above are a Medici heraldic statement, six being typical of the 16th century usage.