I have much admiration for Luis Bermejo, the artist who did the initial stories of the Rook for Warren. Bermejo, born in Madrid, Spain, in 1931, has had an international career, drawing comics for many publishers.
This is the first Rook story, from EERIE #82, March 1977, superbly drawn by Bermejo and written by Bill Dubay. The Rook went on to his own magazine for Warren. After Vampirella, the Rook was the most important character to come from that publisher.