Cover credits confirmed by Comic Reader #124. Colors credit provided by Anthony Tollin.
Inside front cover.
This story was originally 3 pages in House of Mystery #191. The added splash/introduction page is by Howard Chaykin, reprinted in altered form from Forbidden Tales of Dark Mansion (DC, 1972 series) #15 (March 1974) with image of Cain (in lower right) by Berni Wrightson pasted in from the Wrightson splash page in House of Mystery (DC, 1951 Series) #211 (February 1973). "House of Mystery" was added across the top of splash page.
Includes the lyrics to Silent Night, Adeste Fidelis, Kings of Orient, Jingle Bells, Deck the Halls and Away in a Manger.
Inside back cover.