He has also inked over Matt Smith's pencils in Lobster Johnson: The Killer in My Skull, a back-up story in Hellboy: Box Full of Evil #1.
[citation needed] He left the book in 2002 to draw the first spin-off mini-series from Mike Mignola's Hellboy, BPRD: Hollow Earth.
His work in this time period includes: Arkham Asylum: Living Hell with Dan Slott,[1] Hawkman with Justin Gray and Jimmy Palmiotti[3][4] and Seven Soldiers: Zatanna with Grant Morrison and X-Factor with Peter David for Marvel.
In 2009, Sook garnered his highest critical praise to date for his work on the Kamandi story in Wednesday Comics, written by Dave Gibbons.
Sook has been compared to Mike Mignola, Adam Hughes and Kevin Nowlan and has as well been influenced by them, but he also draws inspiration from Alphonse Mucha, JC Leyendecker and Norman Rockwell, among many others.