He was portrayed by Michael Lerner in the film and voiced by Gilbert Gottfried in the cartoon.
Though he is the main villain, his role in the film is small. He is a grumpy, hot tempered, condescending, uncaring man who is feared among his employees. He first appears in Walter's office with a failed children's book that Walter had published he niece read. After complaining about how awful the book and two missing pages and a minus 8, he firmly demands that Walter finds a new book to publish by December 24 or lose his job. Though it is Christmas Eve, Fulton shows no feelings towards the wondrous night. This could imply that Fulton cares little to nothing for the holiday and his family.
After the failed meeting with Miles Finch, Walter sends Buddy off, saying he no longer wants him in his life. During the meeting to discuss new book ideas, Michael bursts in on Walter's meeting with Greenway to frantically tell him that Buddy is gone. After Michael points out that Walter seems to care more about himself than his family, Walter asks Greenway to reschedule. Greenway coldly refuses and threatens to fire him if he leaves, however, Walter stands up to him, and tell him "up yours". As a result, Greenway fires Walter.
Afterwards, his fate is unknown. If he did face defeat, a possibility would be that his company went out of business.
- Though he is referred to onscreen as Mr. Greenway, he is credited as Fulton, so his full name must have been Mr. Fulton Greenway.
- The TV remake marks as the 11th anniversary of the original film.