We’ve done a lot of liquid girls here at Erotic Mad Science, so why not some liquid man? Especially if there’s some imperiled dame tied up in the background? This cover of the September 1941 issue is by Robert Fuqua. Interior art could be a bit thin in some issues of Fantastic Adventures, but this illustration to John Broome’s story “The Pulsating Planet” is pretty dynamic:
This is work (probably) by Albert Magarian (unk.-1991), the husband of the unfortunate Florence Magarian whom we met a few posts back. My “probably” in attribution is because husband and wife were very close collaborators, so this work might reflect contributions by Florence as well. (And I must reflect that Albert lived on for 31 years after Florence died in a mental institution. I…)
This issue is available to be read and downloaded at the Internet Archive.