My original tumblr post was here. This image was originally posted on Tumblr by The Yank with the text “me n my man.” It comes to us via Reginald Juice. To my eye it looks very much like a crop off a sci-fi paperback cover, but diligent searching has failed to reveal any such (or other) source material.
Pretty sure you’re right about the source as an SF paperback. I believe I’ve seen this previously, on the cover of a book, but far enough back in time that I can’t recall. I was thinking of the author Brian Aldiss, but a quick search doesn’t turn up any quite like it. Has very much a 1960s or 70s feel to it.
That alien looks a lot like a Pachycephalasaurus.
That alien looks a lot like a Pachycephalosaurus.