My original tumblr post was here. This image by Frank Kelly Freas was posted on Tumblr by Vintage Geek Culture. While it appears to be paperback cover art, I have been unable to find an example of it used in that context.
Tumblr favorite #2650: Blonde carried off
It’s unused art for “Crash Landing on Iduna,” Arthur Tofte, Laser Books #3, 1975.
Here’s a link with the version you have:
https://squirrelbasket.wordpress.com/2010/05/06/great-sff-illustrators-frank-kelly-freas/
Here’s a link with the modified version they used:
http://www.fantasticliterature.com/tofte-arthur-crash-landing-on-iduna-fm16247
Looks like the creature is saving the woman from an abusive boyfriend.