This is Amazing Stories for October 1947, cover by Robert Gibson Jones. The ISFDB entry for this issue is here. I found this version of the cover at Pulp Covers. You can download and read the entire issue at the Internet Archive.
Pulp Parade #254: This woman is having a bad day II
When a giant, electrified, extraterrestrial dingleberry is trying to eat you, you are having a bad day.
Ain’t that the truth!