Synopsis
Earthmen Penton and Blake are walking on Mars, encountering shape-shifting creatures.
History
First publication: Thrilling Wonder, December 1936
Review
This is a precursor to Who Goes There? but is a standard 1930s SF pulp story. It is interesting and pretty good, but not nearly as exciting or gripping as the later story. It is more along the lines of stories like A Martian Odyssey.
Videos
We have the story in these editions:
The Planeteers / The Ultimate Weapon, paperback, Ace Books, 1966-00-00
All of the stories in the Penton and Blake series:
The Brain Stealers of Mars
The Double Minds
The Immortality Seekers
The Tenth World
The Brain Pirates