The Gospels tells us three different people asked Peter, a disciple of Jesus, whether he knew the person who was on trial inside the home of Caiaphas, the high priest. Each time Peter said he didn't know the man. Jesus had predicted Peter would deny him.
After the third denial, Peter heard a rooster crowing. He then recalled what Jesus had said: You will deny me three times - after the third time, you'll hear a rooster crow.
The church of St. Peter in Gallicantu (which, translated, means "crowing of the cock") commemorates the events with these statues. Note the rooster at the very top of the picture.
Click on the image for a closer inspection.
Image online, courtesy Wikimedia Commons.