"Out on a Limb!" was originally published in I'll Be Damned #4 (January 1971). Bernie Wrightson drew the story in 1970 and shows some more maturity and individual style than his earlier fanzine work. The Frazetta influence is not as evident and there more of a smoothness and confidence than in his 1969 and 1970 short efforts for DC's mystery titles. That may be because of the better reproduction in this black and white story.
"Out on a Limb!" has been reprinted in The Mutants and The Reaper of Love. It was also reprinted in a butchered form in the British magazine Hammer's House of Horror #21 under the title "One Too Many."
I've included at the end of this post Wrightson's cover for the never-published Web of Horror #4. It's possible this story was intended for that magazine.