fiend

His hands were trembling, actually trembling, as if he were some sort of coffee fiend or something. —T. Coraghessan Boyle, The Road to Wellville, 1993

Wodehouse may not have liked Dickens, but he certainly read him. He read like a fiend. —Christopher Hitchens, Times Literary Supplement, 7-13 Sept. 1990

The shameless effrontery of the fiend, at the café, pretending to forget all he had done to her, begging to take up with her again, as if nothing had happened between them a dozen years ago. —Irving Wallace, The Plot, 1967

a fiend in human form

He's a real golf fiend.