Franz Jarnach (14 October 1943 – 16 January 2017), also known by his stage name Mr. Piggi, was a German actor and musician.

He was best known for his role as Schildkröte in the improvisation comedy series Dittsche.

He was a pianist for the 1960s British beat group Lee Curtis and the All-Stars.

Jarnach was born in Bad Godesberg, today a district of Bonn, North Rhine-Westphalia.

Jarnach died from a heart attack on 16 January 2017 in Hamburg.