Jacob Marley

From Memory Alpha, the free Star Trek reference.

Jacob Marley was a character in the Charles Dickens story, A Christmas Carol. He was the partner of Ebenezer Scrooge. When Data was studying method acting in order to understand emotions, he used a holonovel of this story. He recreated Marley's ghost to study fear and how it motivated Scrooge. (TNG: "Devil's Due")

Marley was portrayed by William Glover.