Endrodi István studied art and worked as a designer. He had to stop this activity due to the war recession in 1942 and became an insurance official. While continuing to work as a bookkeeper with an insurance company until 1950, he published his first political and social caricatures from 1945. He contributed to Pesti Izé, Pesti Hírlap and Szabad Száj, and became a staff artist at the Postás Szakszervezet. In the 1950s he was present in Autó-Motorban and in the 1960s he worked for Esti Hírlap.
He was on the staff of Ludas Matyi from 1965 and he made several comics for this publication until his retirement in 1982. Among his comic creations are 'Aranycsillag' (1956), 'A cirkusz' (1957), 'Emil és a detektívek' (1957), 'A vígszínházi csata' (1960), 'Mennydörgés a föld alól' (1968), 'A sárga garnizon' (1970), 'Víkend a pokolban' (1971), 'Farkas szagot hoz a szél' (1972) and 'A rókabarlang titka' (1972).