Lie Down, Killer x 6

1952 Lion paperback original

1956 Crest edition – cover art by James Meese

better image than previously posted

1957 Crest reprint

1958 Crest – cover art by Darcy (Ernest Chiriacka)

1961 Gold Medal reissue – cover art by Barye Phillips

better image than previously posted

undated Fawcett Gold Medal reissue – cover art by Robert McGinnis