Colonel John Coffey is a fictional character from the novel and film adaptation titled "The Green Mile," written by Stephen King. He is portrayed as a gentle giant with a kind heart, who possesses supernatural healing abilities. Coffey is wrongfully convicted of murder and sentenced to death row, where he forms deep connections with the prison guards. Coffey's character explores themes of compassion, injustice, and the moral dilemmas surrounding the death penalty. His unique powers allow him to heal others, which adds complexity to his character and raises questions about the nature of good and evil in the story.