With a little tweaking I think this story, originally published in Atlas Comics' Mystic #23, could have been published in one of that company's humor titles like Crazy. The last panel is a visual joke, and how many stories open up with a collector displaying a petrified vampire and stuffed werewolf?
The Atlas Tales site lists this story as drawn by Romita? with a question mark, so they aren't sure. I scanned it from the Marvel Comics reprint in Vault Of Evil #6, October 1973.