Mr. Wood has a similar appearance to Slappy, except with red hair instead of brown. He also wears a different clothing, including an orange necklace and sneakers.
Mr. Wood carved by an unnamed wizard out of the same coffin wood as his brother, Slappy. Mr. Wood intends to enslave the twin sisters. He eventually got smashed by a steamroller in the book's climax. Thus leaving Slappy to inherit the girls.
In the dream sequence of "Slappy's Nightmare", it's revealed that Mr. Wood's firstname was "Wally".